A DGFiP cyberattack has exposed sensitive tax and cadastral information after attackers allegedly used stolen credentials to access systems belonging to France's Directorate General of Public Finances. The French Public Finances Directorate said investigations found that data linked to 678,000 individuals and professionals had been consulted and extracted during intrusions in June and July 2026. The DGFiP cyberattack incidents were identified after a malicious actor claimed illegitimate access to the French tax authority's information system on August 12 and 13. DGFiP said the intrusions involved the usurpation of identifiers belonging to a DGFiP agent and an authorized third party.

DGFiP Cyberattack Exposed Taxpayer Information

After detecting the intrusions, DGFiP immediately suspended access to the accounts involved. Initial access controls did not identify data theft, which the authority attributed to the sophistication of the attack. A subsequent investigation established that the compromised access points had been used to consult and extract information concerning 678,000 individuals and professionals. The exposed information included reference tax income, family quotient and withholding tax rate for individuals. For businesses, the accessed information included company names and SIREN numbers. Cadastral data, including addresses and property sizes, was also accessed. DGFiP said online accounts belonging to individual and professional users were not compromised, and user IDs and passwords were not affected. The authority notified France's data protection regulator, CNIL, after identifying the data breaches.

Cadastral Data Leak Claim Targets DGFiP

Separately, a hacker using the alias ZeroBytes claimed an attack against DGFiP's Professional Cadastral Data Server (SPDC). According to the claim cited by FrenchBreaches, the alleged extraction contains 252,149 lines of data representing 2,041,778 people, with multiple holders potentially associated with the same property plot. The claimed dataset reportedly includes names, surnames, sex, dates and places of birth, addresses, land identifiers, cadastral sections and parcel numbers, as well as information about rights held on properties. The claim would therefore link individuals to personal information and real estate assets. However, the figures and technical details in this second claim remain allegations by the cybercriminal. The claim that the system could contain information relating to approximately 20 million citizens is also an estimate made by ZeroBytes and does not establish that this number of people was affected.

Investigation Into French Tax Authority Attack Continues

DGFiP said additional security measures were implemented after investigators uncovered new information. These included preventative shutdowns of access to sensitive information systems. Investigations remain underway to determine the precise nature and volume of data extracted and the number of users affected. DGFiP teams are working with France's economic and financial ministries, the High Official for Defence and Security and the National Agency for Information Systems Security, ANSSI. The authority said it will contact affected individuals and professionals directly from the following week by email or letter. Those notifications will identify the information that may have been accessed or extracted and outline any precautionary measures where applicable. DGFiP also said it will file a complaint and provide further information as the investigation progresses. The separate cadastral data breach claim remains subject to confirmation, including the alleged number of affected people, duration of access, methods used to bypass authentication, the full scope of extracted information and whether access remained active when the claim was published. The confirmed DGFiP investigation and the separate ZeroBytes claim therefore present different sets of figures and allegations, with the full scope of the incidents still being determined.

A De Bijenkorf cyberattack involving one of the retailer's external logistics partners has disrupted order processing, returns, and refunds while raising concerns over potential customer data exposure. The Dutch luxury department store chain said the security incident occurred within the systems of a third-party logistics provider, adding that there is currently no evidence that its own infrastructure was compromised.

The Amsterdam-based retailer confirmed that customers can continue placing online orders and stores remain open. However, deliveries, returns, and refunds are expected to take longer than usual as the investigation continues.

De Bijenkorf Confirms Third-Party Security Incident

According to De Bijenkorf, unauthorized individuals gained access to part of its logistics partner's systems. The logistics provider responded by immediately blocking the unauthorized access and implementing additional security measures.

An external investigation is now underway to determine the cause of the incident, its scope, and whether customer information was affected.

As a precaution, De Bijenkorf has informed customers about the incident and submitted a report to the Dutch Data Protection Authority while awaiting the investigation's findings.

What Customer Data Could Be Affected in De Bijenkorf Cyberattack?

The retailer said investigators are still determining whether any personal information has been compromised.

Based on the information currently available, data that may be involved includes:

• Customer names and contact details, including email addresses, postal addresses, and phone numbers.
• Information related to online purchases, such as ordered products, pricing, discounts, delivery details, and the payment method used.
• For business customers, company names and VAT numbers stored in My Account may also be involved.

De Bijenkorf emphasized that sensitive financial information is not part of the incident. The company said payment details, bank account numbers, credit card information, usernames, and passwords were not accessed.

Investigation Continues as Customers Await Confirmation

The retailer said it is still investigating whether individual customers have been affected. Customers whose information is confirmed to be involved will receive direct communication via email from info@debijenkorf.nl.

For those who have not yet received a notification, the company said it cannot currently rule out the possibility that their information was included in the incident until the investigation is completed.

De Bijenkorf also stressed that no login credentials were compromised, meaning unauthorized individuals cannot access customer accounts using stolen usernames or passwords.

Retailer Warns Customers About Phishing Risk

Although the investigation remains ongoing, De Bijenkorf warned customers to stay alert for a possible phishing risk if personal information is ultimately found to have been exposed.

The retailer advised customers not to click on suspicious links or open unexpected attachments. It also reminded customers never to share passwords, payment information, or personal details through email or phone calls.

The company said it will never request credit card details, gift card information, or other sensitive information via email.

Logistics Cyberattacks Continue to Disrupt Supply Chains

The incident adds to a growing list of attacks targeting organizations that support retail operations rather than retailers directly. A logistics cyberattack can interrupt deliveries, returns, and customer service even when the affected retailer's own systems remain operational.

In July 2026, a ransomware attack on Japan's largest refrigerated logistics company disrupted food deliveries across the country, causing supply shortages for restaurant chains, including Kentucky Fried Chicken. The incident demonstrated how cyberattacks on logistics providers can quickly impact downstream retail operations and customer services.

For now, De Bijenkorf said its stores remain open, online ordering continues to operate, and there are no indications that its own systems have been compromised. The retailer said it will provide additional updates as the external investigation establishes whether customer data was affected and the full extent of the incident.

A new outlook from the European Labour Authority and the European Commission’s Directorate-General for Employment, Social Affairs and Inclusion has highlighted how Europe’s approach to AI skills development could shape the future of work by 2040. The report presents several possible futures driven by artificial intelligence adoption, ranging from economic growth and new career opportunities to rising inequality, job insecurity and weakened worker protections. At the centre of all scenarios is one common factor: whether governments, employers and institutions invest early in workforce skills development. According to the findings, AI could create a future where learning becomes more accessible, career growth becomes flexible and workers are better equipped to adapt to changing industries. However, the report also warns that without strong investment in AI skills development, Europe risks widening the gap between workers who can adapt to new technologies and those left behind.

AI-Powered Workplace Could Deepen Inequality 

One of the scenarios described in the report imagines a future where artificial intelligence transforms workplaces so rapidly that many jobs become unrecognisable. In this version of 2040, governments and employers fail to provide adequate workforce training, leaving employees responsible for adapting on their own. The report notes that workers with strong digital and technical skills are likely to benefit the most in such an environment. Meanwhile, employees without access to learning opportunities could struggle to remain employable as automation reshapes industries. The consequences go beyond employment challenges. The report points to growing financial pressure, declining physical and mental wellbeing, and increased social inequality as possible outcomes of an AI transition that does not include inclusive skills development policies. Another scenario paints an even more severe picture of the future. In this case, AI technologies and automation dominate nearly every aspect of work and daily life. A small number of powerful organisations control much of the AI ecosystem, influencing policymaking, economic systems and broader social structures. Under this model, companies rely heavily on automation while reducing investment in employee development. Workers across industries lose jobs as AI systems take over tasks previously performed by humans. The report also warns that weak regulation and limited government oversight could leave workers with little protection. Trade unions, according to the scenario, lose influence in defending labour rights and fair working conditions. The concentration of power among major AI players could also threaten democratic systems while creating environmental concerns linked to large-scale AI infrastructure and energy use.

Slow AI Adoption May still Create a ‘Missed Opportunity’ for Europe

The report also explores a more moderate future in which AI adoption progresses gradually rather than aggressively. While this path appears less disruptive, researchers argue that it could still create long-term problems if Europe fails to prioritise AI skills development. In this “missed opportunity” scenario, the slower pace of AI adoption prevents businesses and workers from fully benefiting from innovation. The report suggests that Europe could lose out on productivity gains, new products and emerging industries if organisations hesitate to adopt AI technologies at scale. For workers, the impact could mean fewer opportunities to move into creative and high-value roles often associated with AI-driven industries. Instead, advanced tasks and innovation-related jobs may remain concentrated among a small group of highly skilled professionals, while much of the workforce continues performing repetitive or lower-value work. Employers may avoid the disruption linked to rapid automation, but they could also fall behind in global competitiveness due to limited innovation and slower operational improvements.

AI Skills Development Seen as Central to Europe’s AI Future

Despite outlining several concerning futures, the report emphasises that these outcomes are not inevitable. Instead, it argues that coordinated action between governments, businesses, educational institutions and workers can help create a more balanced and inclusive AI economy. The European Labour Authority stresses that ongoing workforce skills development will play a central role in determining whether AI benefits society broadly or primarily advantages a small section of the population. The report calls for greater collaboration in promoting lifelong learning, digital education and accessible training programmes that help workers adapt to evolving technologies. It also highlights the importance of policies that support fair AI adoption while protecting workers’ rights and ensuring technological progress contributes to long-term economic and social stability. As Europe continues shaping its AI strategy, the findings serve as a reminder that the future of work may depend less on the technology itself and more on how societies prepare people to work alongside it.

AI models weight trust signals differently in cybersecurity. A comprehensive framework for building entity authority as a security vendor, covering third-party corroboration, author entities, community presence, research credibility, & authority flywheel that compounds citation share.

The post Building Entity Authority in Cybersecurity: The Trust Signals AI Models Actually Weight for Security Vendors appeared first on Security Boulevard.

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A cybersecurity incident has raised concerns after it was revealed that sensitive data associated with the Jurong Region Line (JRL) MRT stations and the Changi NEWater Factory 3 were compromised. The contractor responsible for both critical infrastructure projects, Shanghai Tunnel Engineering Co (Singapore), is currently facing scrutiny as authorities investigate the breach.

Data Compromise Involving Shanghai Tunnel Engineering Co 

The breach primarily affects the civil engineering firm Shanghai Tunnel Engineering Co, which has been engaged in the construction of three key stations along the JRL and the new Changi NEWater Factory 3. While the exact timing of the incident remains unclear, the compromised data has since been identified as tender documents for the projects. These documents, however, are available on the government’s GeBIZ procurement portal, which mitigates concerns over the theft of sensitive information. On April 27, the Land Transport Authority (LTA) responded to public queries by confirming that it was aware of the cybersecurity breach and had reported the matter to the police and other relevant authorities. In an effort to minimize potential risks, the LTA temporarily suspended the contractor’s access to its digital systems, although the breach has not been reported to have disrupted the ongoing construction of the JRL MRT stations.

Impact on Changi NEWater Factory 3 

While the data breach raises alarms, the national water agency PUB (Public Utilities Board) has reassured the public that there has been no access to its digital systems by Shanghai Tunnel Engineering Co. Following an internal investigation, PUB concluded that no sensitive data related to the Changi NEWater Factory 3 had been stolen. The only data compromised were the project tender documents, which, as mentioned, are publicly accessible on GeBIZ. A PUB spokesperson emphasized that the agency maintains a "serious view" of cybersecurity and has advised the contractor to review its security protocols. Despite extensive checks on known ransomware portals and hacker forums, no evidence of leaked data related to the breach has surfaced, alleviating some concerns among stakeholders.

Company’s Response to Cybersecurity Incident 

In a statement issued on April 28, Shanghai Tunnel Engineering Co (Singapore) acknowledged the cybersecurity incident, confirming that it had taken immediate steps to contain the situation. While the company did not specify when the breach occurred, it assured the public that it was cooperating fully with the authorities. Furthermore, the company has enlisted an external cybersecurity specialist to aid in the investigation. "We are cooperating fully with the relevant authorities and kindly request that all parties allow the investigation to proceed without interference," a company representative said. Shanghai Tunnel Engineering Co, established in 1996, is a well-established contractor with significant experience in MRT projects across Singapore. The firm has previously worked on various stations for the Circle, Downtown, and Thomson-East Coast lines. Its latest projects involve critical infrastructure, including the JRL stations and the Changi NEWater Factory 3.

Contract Details and Future Expectations 

In 2019, Shanghai Tunnel Engineering Co was awarded a $465.2 million contract to design and build three JRL stations, Choa Chu Kang, Choa Chu Kang West, and Tengah—along with a 4.3km viaduct connecting them. This work includes integrating the existing Choa Chu Kang MRT station on the North-South Line into the JRL network. In addition to the JRL projects, Shanghai Tunnel Engineering Co is also involved in the construction of the Changi NEWater Factory 3. In November 2025, a $205 million contract was awarded to Sanli M&E Engineering, which formed a joint venture with Shanghai Tunnel Engineering Co in February 2026. The joint venture will be responsible for several key aspects of the factory’s construction, including civil, structural, and architectural works, as well as external and building services. The Changi NEWater Factory 3 is expected to be operational by 2028 and will replace the existing Bedok facility. Once completed, the factory will be capable of producing up to 50 million gallons of NEWater daily, contributing significantly to Singapore's water sustainability efforts.

The Italian Data Protection Authority fine against Poste Italiane and Postepay has reached over €12.5 million, after regulators found unlawful processing of personal data affecting millions of users.

Italy’s Italian Data Protection Authority imposed a €6.6 million penalty on Poste Italiane and €5.8 million on Postepay. The action follows an investigation launched in April 2024 after multiple complaints from users regarding how their data was being handled through mobile applications.

Italian Data Protection Authority Fine Linked to Intrusive App Monitoring

The Italian Data Protection Authority fine centers on how BancoPosta and Postepay apps collected user data. Customers were required to allow monitoring of information stored on their devices, including details about installed and active applications.

According to the companies, this access was necessary to detect malware and prevent fraud in line with payment security requirements. However, the regulator found that the scope of monitoring went too far.

Authorities stated that the data collection methods were not proportionate and resulted in excessive intrusion into users’ private lives. The ruling emphasized that fraud prevention cannot justify blanket access to personal device data.

Multiple Compliance Failures Identified

The investigation behind the Italian Data Protection Authority fine also revealed broader compliance failures. Regulators flagged insufficient transparency in how users were informed about data collection practices.

The companies were also found to have not conducted an adequate Data Protection Impact Assessment. Such assessments are required when processing activities pose high risks to individual privacy.

Further issues included weak security measures, unclear policies on how long data was stored, and irregularities in defining data controller responsibilities. These gaps raised concerns about how user data was governed internally.

As part of the enforcement action, both companies have been ordered to stop the disputed data processing practices if still ongoing. They must also align their data retention policies with regulatory requirements and report compliance to the Authority.

Italian Regulator Steps Up Enforcement

The action reinforces a broader trend of stricter enforcement by the Italian Data Protection Authority across the financial sector. The Italian Data Protection Authority fines Poste Italiane and Postepay case follows another high-profile enforcement action earlier this year involving Intesa Sanpaolo. In March 2026, the regulator imposed a €31.8 million penalty on the bank after uncovering serious lapses in how customer data was protected. The case involved unauthorized access to sensitive information of more than 3,500 customers over a period of more than two years. Investigators found that a single employee had accessed customer records more than 6,600 times without any legitimate business reason. The breach went undetected for months, exposing weaknesses in the bank’s internal monitoring systems.

Insider Risks and Monitoring Gaps under Focus

The Intesa Sanpaolo case highlighted a different but equally critical issue. While Poste Italiane and Postepay were penalized for excessive data collection, the bank was fined for failing to detect misuse of legitimate access. According to the Authority, the bank’s monitoring systems were not designed to identify slow, repeated misuse of access over time. This allowed the unauthorized activity to continue without triggering alerts, even when it involved high-risk individuals such as public figures. Regulators concluded that the controls in place were not aligned with the risks associated with broad internal access to sensitive financial data. The case has since raised concerns about insider threats and the effectiveness of existing detection mechanisms within financial institutions.

Growing Pressure on Financial Services

Together, these cases reflect a tightening regulatory environment in Italy, where financial institutions are being held accountable for both overreach and underperformance in data protection. The Italian Data Protection Authority fines Poste Italiane and Postepay decision highlights the importance of balancing fraud prevention measures with user privacy. Security controls must be proportionate, transparent, and supported by proper risk assessments. At the same time, the Intesa Sanpaolo breach demonstrates that insufficient monitoring can be just as damaging, particularly when insider threats go unnoticed for extended periods. With enforcement actions increasing in scale and frequency, organizations operating in the financial sector are facing mounting pressure to reassess their data governance frameworks. The regulator’s recent decisions make it clear that both excessive data collection and weak oversight can lead to significant financial and reputational consequences.

Letter from group published by MPs blames 12 March glitch on software update to its mobile banking apps

Lloyds Banking Group exposed the personal data of nearly 500,000 customers in an IT glitch that left people’s payments, account details and national insurance numbers visible to other users, a committee of MPs has revealed.

A letter from Lloyds, published by MPs on the Treasury select committee on Friday, blamed the glitch on a software defect introduced during an IT update to its Lloyds, Halifax and Bank of Scotland mobile banking apps overnight into 12 March.

Continue reading...

© Photograph: David Burton/Alamy

© Photograph: David Burton/Alamy

© Photograph: David Burton/Alamy

Over the past few days Cloudflare has been notified through our vulnerability disclosure program and the certificate transparency mailing list that unauthorized certificates were issued by Fina CA for 1.1.1.1, one of the IP addresses used by our public DNS resolver service. From February 2024 to August 2025, Fina CA issued twelve certificates for 1.1.1.1 without our permission. We did not observe unauthorized issuance for any properties managed by Cloudflare other than 1.1.1.1.

We have no evidence that bad actors took advantage of this error. To impersonate Cloudflare's public DNS resolver 1.1.1.1, an attacker would not only require an unauthorized certificate and its corresponding private key, but attacked users would also need to trust the Fina CA. Furthermore, traffic between the client and 1.1.1.1 would have to be intercepted.

While this unauthorized issuance is an unacceptable lapse in security by Fina CA, we should have caught and responded to it earlier. After speaking with Fina CA, it appears that they issued these certificates for the purposes of internal testing. However, no CA should be issuing certificates for domains and IP addresses without checking control. At present all certificates have been revoked. We are awaiting a full post-mortem from Fina.

While we regret this situation, we believe it is a useful opportunity to walk through how trust works on the Internet between networks like ourselves, destinations like 1.1.1.1, CAs like Fina, and devices like the one you are using to read this. To learn more about the mechanics, please keep reading.

Cloudflare operates a public DNS resolver 1.1.1.1 service that millions of devices use to resolve domain names from a human-readable format such as example.com to an IP address like 192.0.2.42 or 2001:db8::2a.

The 1.1.1.1 service is accessible using various methods, across multiple domain names, such as cloudflare-dns.com and one.one.one.one, and also using various IP addresses, such as 1.1.1.1, 1.0.0.1, 2606:4700:4700::1111, and 2606:4700:4700::1001. 1.1.1.1 for Families also provides public DNS resolver services and is hosted on different IP addresses — 1.1.1.2, 1.1.1.3, 1.0.0.2, 1.0.0.3, 2606:4700:4700::1112, 2606:4700:4700::1113, 2606:4700:4700::1002, 2606:4700:4700::1003.

As originally specified in RFC 1034 and RFC 1035, the DNS protocol includes no privacy or authenticity protections. DNS queries and responses are exchanged between client and server in plain text over UDP or TCP. These represent around 60% of queries received by the Cloudflare 1.1.1.1 service. The lack of privacy or authenticity protection means that any intermediary can potentially read the DNS query and response and modify them without the client or the server being aware.

To address these shortcomings, we have helped develop and deploy multiple solutions at the IETF. The two of interest to this post are DNS over TLS (DoT, RFC 7878) and DNS over HTTPS (DoH, RFC 8484). In both cases the DNS protocol itself is mainly unchanged, and the desirable security properties are implemented in a lower layer, replacing the simple use of plain-text in UDP and TCP in the original specification. Both DoH and DoT use TLS to establish an authenticated, private, and encrypted channel over which DNS messages can be exchanged. To learn more you can read DNS Encryption Explained.

During the TLS handshake, the server proves its identity to the client by presenting a certificate. The client validates this certificate by verifying that it is signed by a Certification Authority that it already trusts. Only then does it establish a connection with the server. Once connected, TLS provides encryption and integrity for the DNS messages exchanged between client and server. This protects DoH and DoT against eavesdropping and tampering between the client and server.

The TLS certificates used in DoT and DoH are the same kinds of certificates HTTPS websites serve. Most website certificates are issued for domain names like example.com. When a client connects to that website, they resolve the name example.com to an IP like 192.0.2.42, then connect to the domain on that IP address. The server responds with a TLS certificate containing example.com, which the device validates.

However, DNS server certificates tend to be used slightly differently. Certificates used for DoT and DoH have to contain the service IP addresses, not just domain names. This is due to clients being unable to resolve a domain name in order to contact their resolver, like cloudflare-dns.com. Instead, devices are first set up by connecting to their resolver via a known IP address, such as 1.1.1.1 in the case of Cloudflare public DNS resolver. When this connection uses DoT or DoH, the resolver responds with a TLS certificate issued for that IP address, which the client validates. If the certificate is valid, the client believes that it is talking to the owner of 1.1.1.1 and starts sending DNS queries.

You can see that the IP addresses are included in the certificate Cloudflare’s public resolver uses for DoT/DoH:

Certificate:
  Data:
      Version: 3 (0x2)
      Serial Number:
          02:7d:c8:c5:e1:72:94:ae:c9:ed:3f:67:72:8e:8a:08
      Signature Algorithm: sha256WithRSAEncryption
      Issuer: C=US, O=DigiCert Inc, CN=DigiCert Global G2 TLS RSA SHA256 2020 CA1
      Validity
          Not Before: Jan  2 00:00:00 2025 GMT
          Not After : Jan 21 23:59:59 2026 GMT
      Subject: C=US, ST=California, L=San Francisco, O=Cloudflare, Inc., CN=cloudflare-dns.com
      X509v3 extensions:
          X509v3 Subject Alternative Name:
              DNS:cloudflare-dns.com, DNS:*.cloudflare-dns.com, DNS:one.one.one.one, IP Address:1.0.0.1, IP Address:1.1.1.1, IP Address:162.159.36.1, IP Address:162.159.46.1, IP Address:2606:4700:4700:0:0:0:0:1001, IP Address:2606:4700:4700:0:0:0:0:1111, IP Address:2606:4700:4700:0:0:0:0:64, IP Address:2606:4700:4700:0:0:0:0:6400

The section above describes normal, expected use of Cloudflare public DNS resolver 1.1.1.1 service, using certificates managed by Cloudflare. However, Cloudflare has been made aware of other, unauthorized certificates being issued for 1.1.1.1. Since certificate validation is the mechanism by which DoH and DoT clients establish the authenticity of a DNS resolver, this is a concern. Let’s now dive a little further in the security model provided by DoH and DoT.

Consider a client that is preconfigured to use the 1.1.1.1 resolver service using DoT. The client must establish a TLS session with the configured server before it can send any DNS queries. To be trusted, the server needs to present a certificate issued by a CA that the client trusts. The collection of certificates trusted by the client is also called the root store.

Certificate:
  Data:
      Version: 3 (0x2)
      Serial Number:
          02:7d:c8:c5:e1:72:94:ae:c9:ed:3f:67:72:8e:8a:08
      Signature Algorithm: sha256WithRSAEncryption
      Issuer: C=US, O=DigiCert Inc, CN=DigiCert Global G2 TLS RSA SHA256 2020 CA1

A Certification Authority (CA) is an organisation, such as DigiCert in the section above, whose role is to receive requests to sign certificates and verify that the requester has control of the domain. In this incident, Fina CA issued certificates for 1.1.1.1 without Cloudflare's involvement. This means that Fina CA did not properly check whether the requestor had legitimate control over 1.1.1.1. According to Fina CA:

“They were issued for the purpose of internal testing of certificate issuance in the production environment. An error occurred during the issuance of the test certificates when entering the IP addresses and as such they were published on Certificate Transparency log servers.”

Although it’s not clear whether Fina CA sees it as an error, we emphasize that it is not an error to publish test certificates on Certificate Transparency (more about what that is later on). Instead, the error at hand is Fina CA using their production keys to sign a certificate for an IP address without permission of the controller. We have talked about misuse of 1.1.1.1 in documentation, lab, and testing environments at length. Instead of the Cloudflare public DNS resolver 1.1.1.1 IP address, Fina should have used an IP address it controls itself.

Unauthorized certificates are unfortunately not uncommon, whether due to negligence — such as IdenTrust in November 2024 — or compromise. Famously in 2011, the Dutch CA DigiNotar was hacked, and its keys were used to issue hundreds of certificates. This hack was a wake-up call and motivated the introduction of Certificate Transparency (CT), later formalised in RFC 6962. The goal of Certificate Transparency is not to directly prevent misissuance, but to be able to detect any misissuance once it has happened, by making sure every certificate issued by a CA is publicly available for inspection.

In certificate transparency several independent parties, including Cloudflare, operate public logs of issued certificates. Many modern browsers do not accept certificates unless they provide proof in the form of signed certificate timestamps (SCTs) that the certificate has been logged in at least two logs. Domain owners can therefore monitor all public CT logs for any certificate containing domains they care about. If they see a certificate for their domains that they did not authorize, they can raise the alarm. CT is also the data source for public services such as crt.sh and Cloudflare Radar’s certificate transparency page.

Not all clients require proof of inclusion in certificate transparency. Browsers do, but most DNS clients don’t. We were fortunate that Fina CA did submit the unauthorized certificates to the CT logs, which allowed them to be discovered.

Our immediate concern was that someone had maliciously used the certificates to impersonate the 1.1.1.1 service. Such an attack would require all the following:

1. An attacker would require a rogue certificate and its corresponding private key.

2. Attacked clients would need to trust the Fina CA.

3. Traffic between the client and 1.1.1.1 would have to be intercepted.

In light of this incident, we have reviewed these requirements one by one:

1. We know that a certificate was issued without Cloudflare's involvement. We must assume that a corresponding private key exists, which is not under Cloudflare's control. This could be used by an attacker. Fina CA wrote to us that the private keys were exclusively in Fina’s controlled environment and were immediately destroyed even before the certificates were revoked. As we have no way to verify this, we have and continue to take steps to detect malicious use as described in point 3.

2. Furthermore, some clients trust Fina CA. It is included by default in Microsoft’s root store and in an EU Trust Service provider. We can exclude some clients, as the CA certificate is not included by default in the root stores of Android, Apple, Mozilla, or Chrome. These users cannot have been affected with these default settings. For these certificates to be used nefariously, the client’s root store must include the Certification Authority (CA) that issued them. Upon discovering the problem, we immediately reached out to Fina CA, Microsoft, and the EU Trust Service provider. Microsoft responded quickly, and started rolling out an update to their disallowed list, which should cause clients that use it to stop trusting the certificate.

3. Finally, we have launched an investigation into possible interception between users and 1.1.1.1. The first way this could happen is when the attacker is on-path of the client request. Such man-in-the-middle attacks are likely to be invisible to us. Clients will get responses from their on-path middlebox and we have no reliable way of telling that is happening. On-path interference has been a persistent problem for 1.1.1.1, which we’ve been working on ever since we announced 1.1.1.1.

A second scenario can occur when a malicious actor is off-path, but is able to hijack 1.1.1.1 routing via BGP. These are scenarios we have discussed in a previous blog post, and increasing adoption of RPKI route origin validation (ROV) makes BGP hijacks with high penetration harder. We looked at the historical BGP announcements involving 1.1.1.1, and have found no evidence that such routing hijacks took place.

Although we cannot be certain, so far we have seen no evidence that these certificates have been used to impersonate Cloudflare public DNS resolver 1.1.1.1 traffic. In later sections we discuss the steps we have taken to prevent such impersonation in the future, as well as concrete actions you can take to protect your own systems and users.

All unauthorized certificates for 1.1.1.1 were valid for exactly one year and included other domain names. Most of these domain names are not registered, which indicates that the certificates were issued without proper domain control validation. This violates sections 3.2.2.4 and 3.2.2.5 of the CA/Browser Forum’s Baseline Requirements, and sections 3.2.2.3 and 3.2.2.4 of the Fina CA Certificate Policy.

The full list of domain names we identified on the unauthorized certificates are as follows:

fina.hr
ssltest5
test.fina.hr
test.hr
test1.hr
test11.hr
test12.hr
test5.hr
test6
test6.hr
testssl.fina.hr
testssl.finatest.hr
testssl.hr
testssl1.finatest.hr
testssl2.finatest.hr

It’s also worth noting that the Subject attribute points to a fictional organisation TEST D.D., as can be seen on this unauthorized certificate:

        Serial Number:
            a5:30:a2:9c:c1:a5:da:40:00:00:00:00:56:71:f2:4c
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=HR, O=Financijska agencija, CN=Fina RDC 2015
        Validity
            Not Before: Nov  2 23:45:15 2024 GMT
            Not After : Nov  2 23:45:15 2025 GMT
        Subject: C=HR, O=TEST D.D., L=ZAGREB, CN=testssl.finatest.hr, serialNumber=VATHR-32343828408.306
        X509v3 extensions:
            X509v3 Subject Alternative Name:
                DNS:testssl.finatest.hr, DNS:testssl2.finatest.hr, IP Address:1.1.1.1

All timestamps are UTC. All certificates are identified by their date of validity.

The first certificate was issued to be valid starting February 2024, and revoked 33 min later. 11 certificate issuances with common name 1.1.1.1 followed from February 2024 to August 2025. Public reports have been made on Hacker News and on the certificate-transparency mailing list early in September 2025, which Cloudflare responded to.

While responding to the incident, we identified the full list of misissued certificates, their revocation status, and which clients trust them.

The full timeline for the incident is as follows.

Date & Time (UTC)	Event Description
2024-02-18 11:07:33	First certificate issuance revoked on 2024-02-18 11:40:00
2024-09-25 08:04:03	Issuance revoked on 2024-11-06 07:36:05
2024-10-04 07:55:38	Issuance revoked on 2024-10-04 07:56:56
2024-10-04 08:05:48	Issuance revoked on 2024-11-06 07:39:55
2024-10-15 06:28:48	Issuance revoked on 2024-11-06 07:35:36
2024-11-02 23:45:15	Issuance revoked on 2024-11-02 23:48:42
2025-03-05 09:12:23	Issuance revoked on 2025-03-05 09:13:22
2025-05-24 22:56:21	Issuance revoked on 2025-09-04 06:13:27
2025-06-28 23:05:32	Issuance revoked on 2025-07-18 07:01:27
2025-07-18 07:05:23	Issuance revoked on 2025-07-18 07:09:45
2025-07-18 07:13:14	Issuance revoked on 2025-09-04 06:30:36
2025-08-26 07:49:00	Last certificate issuance revoked on 2025-09-04 06:33:20
2025-09-01 05:23:00	HackerNews submission about a possible unauthorized issuance
2025-09-02 04:50:00	Report shared with us on HackerOne, but was mistriaged
2025-09-03 02:35:00	Second report shared with us on HackerOne, but also mistriaged.
2025-09-03 10:59:00	Report sent on the public certificate-transparency@googlegroups.com mailing picked up by the team.
2025-09-03 11:33:00	First response by Cloudflare on the mailing list about starting the investigation
2025-09-03 12:08:00	Incident declared
2025-09-03 12:16:00	Notification of an unauthorised issuance sent to Fina CA, Microsoft Root Store, and EU Trust service provider
2025-09-03 12:23:00	Cloudflare identifies an initial list of nine rogue certificates
2025-09-03 12:24:00	Outreach to Fina CA to inform them about the unauthorized issuance, requesting revocation
2025-09-03 12:26:00	Identify the number of requests served on 1.1.1.1 IP address, and associated names/services
2025-09-03 12:42:00	As a precautionary measure, began investigation to rule out the possibility of a BGP hijack for 1.1.1.1
2025-09-03 18:48:00	Second notification of the incident to Fina CA
2025-09-03 21:27:00	Microsoft Root Store notifies us that they are preventing further use of the identified unauthorized certificates by using their quick-revocation mechanism.
2025-09-04 06:13:27	Fina revoked all certificates.
2025-09-04 12:44:00	Cloudflare receives a response from Fina indicating “an error occurred during the issuance of the test certificates when entering the IP addresses and as such they were published on Certificate Transparency log servers. [...] Fina will eliminate the possibility of such an error recurring.”

Cloudflare has invested from the very start in the Certificate Transparency ecosystem. Not only do we operate CT logs ourselves, we also run a CT monitor that we use to alert customers when certificates are mis-issued for their domains.

It is therefore disappointing that we failed to properly monitor certificates for our own domain. We failed three times. The first time because 1.1.1.1 is an IP certificate and our system failed to alert on these. The second time because even if we were to receive certificate issuance alerts, as any of our customers can, we did not implement sufficient filtering. With the sheer number of names and issuances we manage it has not been possible for us to keep up with manual reviews. Finally, because of this noisy monitoring, we did not enable alerting for all of our domains. We are addressing all three shortcomings.

We double-checked all certificates issued for our names, including but not limited to 1.1.1.1, using certificate transparency, and confirmed that as of 3 September, the Fina CA issued certificates are the only unauthorized issuances. We contacted Fina, and the root programs we know that trust them, to ask for revocation and investigation. The certificates have been revoked.

Despite no indication of usage of these certificates so far, we take this incident extremely seriously. We have identified several steps we can take to address the risk of these sorts of problems occurring in the future, and we plan to start working on them immediately:

Alerting: Cloudflare will improve alerts and escalation for issuance of certificates for missing Cloudflare owned domains including 1.1.1.1 certificates.

Transparency: The issuance of these unauthorised 1.1.1.1 certificates were detected because Fina CA used Certificate Transparency. Transparency inclusion is not enforced by most DNS clients, which implies that this detection was a lucky one. We are working on bringing transparency to non-browser clients, in particular DNS clients that rely on TLS.

Bug Bounty: Our procedure for triaging reports made through our vulnerability disclosure program was the cause for a delayed response. We are working to revise our triaging process to ensure such reports get the right visibility.

Monitoring: During this incident, our team relied on crt.sh to provide us a convenient UI to explore CA issued certificates. We’d like to give a shout to the Sectigo team for maintaining this tool. Given Cloudflare is an active CT Monitor, we have started to build a dedicated UI to explore our data in Radar. We are looking to enable exploration of certs with IP addresses as common names to Radar as well.

This incident demonstrates the disproportionate impact that the current root store model can have. It is enough for a single certification authority going rogue for everyone to be at risk.

If you are an IT manager with a fleet of managed devices, you should consider whether you need to take direct action to revoke these unauthorized certificates. We provide the list in the timeline section above. As the certificates have since been revoked, it is possible that no direct intervention should be required; however, system-wide revocation is not instantaneous and automatic and hence we recommend checking.

If you are tasked to review the policy of a root store that includes Fina CA, you should take immediate actions to review their inclusion in your program. The issue that has been identified through the course of this investigation raises concerns, and requires a clear report and follow-up from the CA. In addition, to make it possible to detect future such incidents, you should consider having a requirement for all CAs in your root store to participate in Certificate Transparency. Without CT logs, problems such as the one we describe here are impossible to address before they result in impact to end users.

We are not suggesting that you should stop using DoH or DoT. DNS over UDP and TCP are unencrypted, which puts every single query and response at risk of tampering and unauthorised surveillance. However, we believe that DoH and DoT client security could be improved if clients required that server certificates be included in a certificate transparency log.

This event is the first time we have observed a rogue issuance of a certificate used by our public DNS resolver 1.1.1.1 service. While we have no evidence this was malicious, we know that there might be future attempts that are.

We plan to accelerate how quickly we discover and alert on these types of issues ourselves. We know that we can catch these earlier, and we plan to do so.

The identification of these kinds of issues rely on an ecosystem of partners working together to support Certificate Transparency. We are grateful for the monitors who noticed and reported this issue.