Welcome to the 26th edition of Cloudflare's DDoS Threat Report. This edition covers the third quarter of 2026 — July, August, and September — and returns the series to its quarterly cadence following the combined H1 2026 volume. The analysis is produced by Cloudforce One, Cloudflare's Threat Intelligence organization, providing a comprehensive analysis of the evolving threat landscape of Distributed Denial of Service (DDoS) attacks based on data from the Cloudflare network.

Key insights

1. Short-burst, low-bandwidth attacks lasting under 10 minutes and 1 Gbps surged by 208%. Conversely, hyper-volumetric attacks exceeding 1 Tbps plummeted by nearly 69% from Q2, possibly a reflection of law enforcement actions against four major Internet of Things (IoT) botnets earlier in the year. However, variants continue to emerge, proving that IoT botnets remain a durable, high-volume threat to network infrastructure.
2. Threat actors dramatically shifted their reflection and amplification tactics, abruptly abandoning CLDAP floods, which collapsed by 99.5% quarter-over-quarter. Instead, attackers pivoted heavily toward other connectionless protocols, driving a 215% surge in DNS amplification and a 122% increase in general UDP floods.
3. Attack targets broadened significantly across both industries and geographies, with the United States reclaiming the most-attacked position from China. Canada and Israel experienced sharp spikes in targeted attacks — jumping 10 and 7 spots respectively — while juggling geopolitical tensions, trade disputes, and contentious domestic events. At the same time, the operational focus shifted away from media organizations toward a wider array of industry targets, including consumer services, Internet infrastructure, and adult entertainment.

Q3 by the numbers: 8,200 DDoS attacks every hour

Across its network in the third quarter of 2026, Cloudflare autonomously mitigated 18.2 million network-layer DDoS attacks and 14.4 trillion HTTP DDoS requests. That works out to approximately 8,226 network-layer DDoS attacks per hour, or about 197,400 per day — one attack every 0.44 seconds. The quarter's mitigated traffic totaled 272.6 PB at the network layer and 95.1 PB at the HTTP layer.

More swarms, fewer giants

Short-burst, mid-range, high-count attacks — the operational signature of DDoS-for-hire "booter" services — accelerated this quarter. These attacks primarily targeted computer software, gambling and casinos, and information technology industries. Cloudflare autonomously mitigated 18.2 million network-layer DDoS attacks in Q3 2026, a +208% increase from the same quarter in 2025:

• 96% ended in under 10 minutes
• 98% stayed under 1 Gbps, more than enough to overwhelm a server or website

On the other hand, network-level hyper-volumetric attacks (those exceeding 1 Tbps) reversed course, dropping to 251 attacks in Q3 from 805 in Q2 — coinciding with law enforcement action in early 2026 that dismantled four of the largest IoT DDoS botnets: Aisuru, KimWolf, JackSkid, and Mossad.

Still, IoT-based botnets remain a durable high-volume threat as the ecosystem churns through new variants such as Dysphoria and Evooo1Bot. Mirai-classified mitigation peaked in August at 57.23 PB, representing 46.5% of all mitigated network-layer bytes in Q3, including four days — August 16, 19, 23, and 25 — that each cleared three petabytes. The quarter's longest sustained Mirai attack ran 49.7 hours between August 19 and August 21.

Vector shifts: the collapse of CLDAP and rise of UDP

The most dramatic vector shift of the quarter was downward. CLDAP (Connectionless Lightweight Directory Access Protocol) attacks — where small queries with a forged victim IP address trick public domain controllers (UDP 389) into reflecting massive, amplified responses back at the target — experienced a dramatic +580% quarter-over-quarter surge in the first half of the year before collapsing to just 0.05% of attacks in Q3.

Meanwhile, DNS amplification surged 215% to account for 3.43% of all network-layer attacks, exploiting open DNS resolvers in a similar reflection-and-amplification pattern to CLDAP: small spoofed queries, large replies directed at the victim. Other UDP floods climbed from 14.06% to 31.31% of network-layer attacks. UDP is a connectionless transport protocol, which makes it a convenient vehicle for raw volumetric attacks: attackers send large numbers of UDP packets to random or specific ports on the target, forcing the target to check for a listening application and respond, consuming its network and compute resources.

Most-attacked industry

While Media, Production & Publishing remained the most-attacked industry in Q3 2026, its overall share is roughly a quarter of its Q2 level, and the focus has moved across a wider set of industries. Internet rose from outside the top 10 to #6; Consumer Services and Adult Entertainment also climbed in, reaching #8 and #9 respectively.

Most-attacked locations

Geographic surges: Canada and Israel climb the ranks

Adding to an already turbulent period of bilateral trade disputes, Canada jumped from #16 to #6, driven by attacks against its Retail, Telecommunications, Service providers & carriers, and Marketing & advertising industries.

Israel moved 7 spots to take #10 as a result of sustained DDoS activity in mid-September. While this period was marked by contentious decisions ahead of parliamentary elections and the Rosh Hashanah holiday, there was also a massive, documented surge in hostile cyber warfare targeting Israel this year.

Top 10

The United States was the most-attacked location in Q3 2026, while China was number #2 and Indonesia rose into the top three at 2.93% of total attacks. The U.S.-China pairing at the top is consistent with the first half of 2026, when China finished #1 and the U.S. #2; the countries have traded positions as attention and attacker preferences shift.

Strengthening global defenses and helping to defend the Internet

Cloudflare's network is designed to absorb this kind of growth in DDoS threats. Every service on our network is protected by free, unmetered DDoS protection that runs at every one of our 330+ cities globally, backed by 500 Tbps of network capacity. Autonomy is the point: our systems detect and mitigate attacks without human intervention. And they need to, because as this quarter's distributions make clear, most attacks end long before a human analyst could see the alert, and the largest attacks still regularly exceed 1 Tbps at a cadence measured in hundreds per quarter.

To help hosting providers, cloud computing platforms, and Internet service providers identify and take down the abusive IP addresses and accounts that launch these attacks, we leverage Cloudflare's unique vantage point on DDoS attacks to provide a free DDoS Botnet Threat Feed for Service Providers.

Over 800 networks worldwide have signed up for this feed, and we've already seen great collaboration across the community to take down botnet nodes. For a continuously-updated view of attack trends across the Internet, visit Cloudflare Radar.    

About Cloudforce One

Driven by a mission to help defend the Internet, Cloudforce One draws on telemetry from Cloudflare's global network — which protects more than 20% of the web — to drive threat research and operational response, protecting critical systems for millions of organizations worldwide.

Welcome to the 24th edition of Cloudflare’s Quarterly DDoS Threat Report. In this report, Cloudforce One offers a comprehensive analysis of the evolving threat landscape of Distributed Denial of Service (DDoS) attacks based on data from the Cloudflare network. In this edition, we focus on the fourth quarter of 2025, as well as share overall 2025 data.

The fourth quarter of 2025 was characterized by an unprecedented bombardment launched by the Aisuru-Kimwolf botnet, dubbed “The Night Before Christmas" DDoS attack campaign. The campaign targeted Cloudflare customers as well as Cloudflare’s dashboard and infrastructure with hyper-volumetric HTTP DDoS attacks exceeding rates of 200 million requests per second (rps), just weeks after a record-breaking 31.4 Terabits per second (Tbps) attack.

1. DDoS attacks surged by 121% in 2025, reaching an average of 5,376 attacks automatically mitigated every hour.

2. In the final quarter of 2025, Hong Kong jumped 12 places, making it the second most DDoS’d place on earth. The United Kingdom also leapt by an astonishing 36 places, making it the sixth most-attacked place.

3. Infected Android TVs — part of the Aisuru-Kimwolf botnet — bombarded Cloudflare’s network with hyper-volumetric HTTP DDoS attacks, while Telcos emerged as the most-attacked industry.

In 2025, the total number of DDoS attacks more than doubled to an incredible 47.1 million. Such attacks have soared in recent years: The number of DDoS attacks spiked 236% between 2023 and 2025.

In 2025, Cloudflare mitigated an average of 5,376 DDoS attacks every hour — of these, 3,925 were network-layer DDoS attacks and 1,451 were HTTP DDoS attacks. 

The most substantial growth was in network-layer DDoS attacks, which more than tripled year over year. Cloudflare mitigated 34.4 million network-layer DDoS attacks in 2025, compared to 11.4 million in 2024.

A substantial portion of the network-layer attacks — approximately 13.5 million — targeted global Internet infrastructure protected by Cloudflare Magic Transit and Cloudflare’s infrastructure directly, as part of an 18-day DDoS campaign in the first quarter of 2025. Of these attacks, 6.9 million targeted Magic Transit customers while the remaining 6.6 million targeted Cloudflare directly. 

This assault was a multi-vector DDoS campaign comprising SYN flood attacks, Mirai-generated DDoS attacks, and SSDP amplification attacks to name a few. Our systems detected and mitigated these attacks automatically. In fact, we only discovered the campaign while preparing our DDoS threat report for 2025 Q1 — an example of how effective Cloudflare’s DDoS mitigation is!

In the final quarter of 2025, the number of DDoS attacks grew by 31% over the previous quarter and 58% over 2024. Network-layer DDoS attacks fueled that growth. In 2025 Q4, network-layer DDoS attacks accounted for 78% of all DDoS attacks. The amount of HTTP DDoS attacks remained the same, but surged in their size to rates that we haven’t seen since the HTTP/2 Rapid Reset DDoS campaign in 2023. These recent surges were launched by the Aisuru-Kimwolf botnet, which we will cover in the next section. 

On Friday, December 19, 2025, the Aisuru-Kimwolf botnet began bombarding Cloudflare infrastructure and Cloudflare customers with hyper-volumetric DDoS attacks. What was new in this campaign was its size: The botnet used hyper-volumetric HTTP DDoS attacks exceeding rates of 20 million requests per second (Mrps).

The Aisuru-Kimwolf botnet is a massive collection of malware-infected devices, primarily Android TVs. The botnet comprises an estimated 1-4 million infected hosts. It is capable of launching DDoS attacks that can cripple critical infrastructure, crash most legacy cloud-based DDoS protection solutions, and even disrupt the connectivity of entire nations.

Throughout the campaign, Cloudflare’s autonomous DDoS defense systems detected and mitigated all of the attacks: 384 packet-intensive attacks, 329 bit-intensive attacks, and 189 request-intensive attacks, for a total of 902 hyper-volumetric DDoS attacks, averaging 53 attacks a day.

The average size of the hyper-volumetric DDoS attacks during the campaign were 3 Bpps, 4 Tbps, and 54 Mrps. The maximum rates recorded during the campaign were 9 Bpps, 24 Tbps, and 205 Mrps.

To put that in context, the scale of a 205 Mrps DDoS attack is comparable to the combined populations of the UK, Germany, and Spain all simultaneously typing a website address and then hitting 'enter’ at the same second.

While highly dramatic, The Night Before Christmas campaign accounted for only a small portion of the hyper-volumetric DDoS attacks we saw throughout the year.

Throughout 2025, Cloudflare observed a continuous increase in hyper-volumetric DDoS attacks. In 2025 Q4, hyper-volumetric attacks increased by 40% compared to the previous quarter.

As the number of attacks increased over the course of 2025, the size of the attacks increased as well, growing by over 700% compared to the large attacks seen in late 2024, with one reaching 31.4 Tbps in a DDoS attack that lasted just 35 seconds. The graph below portrays the rapid growth in DDoS attack sizes as seen and blocked by Cloudflare — each one a world record, i.e. the largest ever disclosed publicly by any company at the time.

Like all of the other attacks, the 31.4 Tbps DDoS attack was detected and mitigated automatically by Cloudflare’s autonomous DDoS defense, which was able to adapt and quickly lock on to botnets such as Aisuru-Kimwolf.

Most of the hyper-volumetric DDoS attacks targeted Cloudflare customers in the Telecommunications, Service Providers and Carriers industry. Cloudflare customers in the Gaming industry and customers providing Generative AI services were also heavily targeted. Lastly, Cloudflare’s own infrastructure itself was targeted by multiple attack vectors such as HTTP floods, DNS attacks and UDP flood.

When analyzing DDoS attacks of all sizes, the Telecommunications, Service Providers and Carriers industry was also the most targeted. Previously, the Information Technology & Services industry held that unlucky title.

The Gambling & Casinos and Gaming industries ranked third and fourth, respectively. The quarter’s biggest changes in the top 10 were the Computer Software and Business Services industries, which both climbed several spots. 

The most-attacked industries are defined by their role as critical infrastructure, a central backbone for other businesses, or their immediate, high-stakes financial sensitivity to service interruption and latency.

The DDoS landscape saw both predictable stability and dramatic shifts among the world's most-attacked locations. Targets like China, Germany, Brazil, and the United States were the top five, demonstrating persistent appeal for attackers. 

Hong Kong made a significant move, jumping twelve spots to land at number two. However, the bigger story was the meteoric rise of the United Kingdom, which surged an astonishing 36 places this quarter, making it the sixth most-attacked location.  

Vietnam held its place as the seventh most-attacked location, followed by Azerbaijan in eighth, India in ninth, and Singapore as number ten.

Bangladesh dethroned Indonesia as the largest source of DDoS attacks in the fourth quarter of 2025. Indonesia dropped to the third spot, after spending a year as the top source of DDoS attacks. Ecuador also jumped two spots, making it the second-largest source.

Notably, Argentina soared an incredible twenty places, making it the fourth-largest source of DDoS attacks. Hong Kong rose three places, taking fifth place. Ukraine came in sixth place, followed by Vietnam, Taiwan, Singapore, and Peru.

The top 10 list of attack source networks reads like a list of Internet giants, revealing a fascinating story about the anatomy of modern DDoS attacks. The common thread is clear: Threat actors are leveraging the world's most accessible and powerful network infrastructure — primarily large, public-facing services. 

We see most DDoS attacks coming from IP addresses associated with Cloud Computing Platforms and Cloud Infrastructure Providers, including DigitalOcean (AS 14061), Microsoft (AS 8075), Tencent (AS 132203), Oracle (AS 31898), and Hetzner (AS 24940). This demonstrates the strong link between easily-provisioned virtual machines and high-volume attacks. These cloud sources, heavily concentrated in the United States, are closely followed by a significant presence of attacks coming from IP addresses associated with traditional Telecommunications Providers (Telcos). These Telcos, primarily from the Asia-Pacific region (including Vietnam, China, Malaysia, and Taiwan), round out the rest of the top 10.

This geographic and organizational diversity confirms a two-pronged attack reality: While the sheer scale of the highest-ranking sources often originates from global cloud hubs, the problem is truly worldwide, routed through the Internet's most critical pathways from across the globe. In many DDoS attacks, we see thousands of various source ASNs, highlighting the truly global distribution of botnet nodes.

To help hosting providers, cloud computing platforms and Internet service providers identify and take down the abusive IP addresses/accounts that launch these attacks, we leverage Cloudflare’s unique vantage point on DDoS attacks to provide a free DDoS Botnet Threat Feed for Service Providers. 

Over 800 networks worldwide have signed up for this feed, and we’ve already seen great collaboration across the community to take down botnet nodes.

DDoS attacks are rapidly growing in sophistication and size, surpassing what was previously imaginable. This evolving threat landscape presents a significant challenge for many organizations to keep pace. Organizations currently relying on on-premise mitigation appliances or on-demand scrubbing centers may benefit from re-evaluating their defense strategy.

Cloudflare is dedicated to offering free, unmetered DDoS protection to all its customers, regardless of the size, duration, or volume of attacks, leveraging its vast global network and autonomous DDoS mitigation systems.

Driven by a mission to help defend the Internet, Cloudforce One leverages telemetry from Cloudflare’s global network — which protects approximately 20% of the web — to drive threat research and operational response, protecting critical systems for millions of organizations worldwide.

_{(Correction on August 19, 2025: This post was updated to correct and clarify details about the vulnerability and the HTTP/2 protocol.)}

On August 13, security researchers at Tel Aviv University disclosed a new HTTP/2 denial-of-service (DoS) vulnerability that they are calling MadeYouReset (CVE-2025-8671). This vulnerability exists in a limited number of unpatched HTTP/2 server implementations that do not accurately track use of server-sent stream resets, which can lead to resource consumption. If you’re using Cloudflare for HTTP DDoS mitigation, you’re already protected from MadeYouReset.

Cloudflare was informed of this vulnerability in May through a coordinated disclosure process, and we were able to confirm that our systems were not susceptible. We foresaw this sort of attack while mitigating the "Netflix vulnerabilities" in 2019, and added even stronger defenses in response to Rapid Reset (CVE-2023-44487) in 2023. MadeYouReset and Rapid Reset are two conceptually similar attacks that exploit a fundamental feature within the HTTP/2 specification (RFC 9113): stream resets. In the HTTP/2 protocol, a client initiates a bidirectional stream that carries an HTTP request/response exchange, represented as frames sent between the client and server. Typically, HEADERS and DATA frames are used for a complete exchange.  Endpoints can use the RST_STREAM frame to prematurely terminate a stream, essentially cancelling operations and signalling that it won’t process any more request or response data. Furthermore, HTTP/2 requires that RST_STREAM is sent when there are protocol errors related to the stream. For example, section 6.1 of RFC 9113 requires that when a DATA frame is received under the wrong circumstances, "...the recipient MUST respond with a stream error (Section 5.4.2) of type STREAM_CLOSED". 

The vulnerability exploited by both MadeYouReset and Rapid Reset lies in the potential for malicious actors to abuse this stream reset mechanism. By repeatedly causing stream resets, attackers can overwhelm a server's resources. While the server is attempting to process and respond to a multitude of requests, the rapid succession of resets forces it to expend computational effort on starting and then immediately discarding these operations. This can lead to resource exhaustion and impact the availability of the targeted server for legitimate users; as described previously, the main difference between the two attacks is that Rapid Reset exploits client-sent resets, while MadeYouReset exploits server-sent resets. It works by using a client to persuade a server into resetting streams via intentionally sending frames that trigger protocol violations, which in turn trigger stream errors.

RFC 9113 details a number of denial-of-service considerations. Fundamentally, the protocol provides many features with legitimate uses that can be exploited by attackers with nefarious intent. Implementations are advised to harden themselves: "An endpoint that doesn't monitor use of these features exposes itself to a risk of denial of service. Implementations SHOULD track the use of these features and set limits on their use."

Fortunately, the MadeYouReset vulnerability only impacts a relatively small number of HTTP/2 implementations. In most major HTTP/2 implementations already in widespread use today, the proactive measures taken to implement RFC 9113 guidance and counter Rapid Reset in 2023 have also provided substantial protection against MadeYouReset, limiting its potential impact and preventing a similarly disruptive event.

A note about Cloudflare’s Pingora and its users: Our open-sourced Pingora framework uses the popular Rust-language h2 library for its HTTP/2 support. Versions of h2 prior to 0.4.11 were potentially susceptible to MadeYouReset. Users of Pingora can patch their applications by updating their h2 crate version using the cargo update command. Pingora does not itself terminate inbound HTTP connections to Cloudflare’s network, meaning this vulnerability could not be exploited against Cloudflare’s infrastructure.

We would like to credit researchers Gal Bar Nahum, Anat Bremler-Barr, and Yaniv Harel of Tel Aviv University for discovering this vulnerability and thank them for their leadership in the coordinated disclosure process. Cloudflare always encourages security researchers to submit vulnerabilities like this to our HackerOne Bug Bounty program.