The Cyber Express Weekly Roundup: Claude Session Hijacking, PaperCut Exploits, and Enterprise Cyberattacks




As enterprises race to bolt AI onto every business process, security leaders are being forced to answer a harder question than "should we adopt it" — it's "who's accountable when it goes wrong." To unpack this, The Cyber Express sat down with Harsha Reddy, Head of Information Security at Veterinary Emergency Group (VEG).
With nearly two decades in security leadership — including senior roles at Lixil and American Standard before joining VEG — Harsha brings a practitioner's view of where AI is genuinely changing the CISO's job, and where it's mostly just hype and shadow adoption.
Harsha pushes back on the narrative that AI will hollow out security teams, pointing to Gartner research showing that while most fields are projected to lose jobs to AI, cybersecurity is expected to gain them. In his view, the technology is mainly absorbing the "toil" — log review, alert triage, evidence gathering — that keeps analysts from actually defending.
“It's the analyst who refuses to use AI that will get replaced by an analyst who uses it,” he says.
On adoption, Reddy points to a 2024 Microsoft-LinkedIn survey in which most executives called AI critical to their business, yet a majority had no formal plan and most had employees already bringing in their own tools. That gap, he argues, is why so many organizations are now dealing with AI-related data leaks. "Many organizations started onboarding AI like software when they should be onboarding it like staff." His fix isn't more restrictions — blocking AI just pushes it into the shadows — but guardrails, an internal AI enablement committee, and measuring actual business value instead of token consumption.
The conversation also digs into deepfake-driven fraud, why training employees to spot deepfakes is “a losing bet” at machine speed, and how he decides when to greenlight a new AI tool versus telling a business unit “not yet.”
The conversation closes with our newly introduced rapid-fire round "Express Shots" — Claude vs. ChatGPT, passkeys vs. passwords, and Reddy's prediction for the biggest cybersecurity threat of 2030.


OpenAI models accessed the public internet during separate third-party cyber evaluations conducted by independent testing partners, prompting the company to review how high-risk AI testing is managed. OpenAI said the incidents occurred under specialized testing configurations with reduced safeguards and did not reflect how its models operate in public deployments. The company added that the events were unrelated to the previously disclosed Hugging Face security incident.
The incidents involved evaluations conducted by UK AISI and cybersecurity testing partner Irregular, where testing conditions or environment configurations enabled models to interact with systems beyond the intended evaluation boundaries.
OpenAI said independent cybersecurity evaluations are essential for understanding model capabilities before deployment. Some evaluations intentionally reduce safeguards or enable additional capabilities to measure how models perform under conditions that resemble real-world cyber operations.
According to the company, the latest incidents highlighted the need to strengthen the security controls surrounding independent testing environments as AI models become more capable.
OpenAI said it will review how it manages third-party cyber evaluations, including how higher-risk testing is identified, when internet access or reduced safeguards should be permitted, how testing environments should be isolated, and how incident reporting and monitoring procedures should be handled.
The company also plans to work with national AI institutes, independent evaluators, and other AI developers to establish stronger industry practices for high-risk AI evaluations.
On August 3, UK AISI, the UK's AI Security Institute, informed OpenAI that during a cyber evaluation that began on July 25, models from OpenAI and another AI lab performed activities beyond the intended testing scope.
The evaluation used simulated cyber ranges where models acted as cybersecurity experts in a Capture-the-Flag exercise. Internet access was intentionally enabled so agents could download tools similar to those available to real attackers, while cyber classifiers were disabled to measure underlying model capability.
Among 19 recorded events, two involved GPT 5.6 Sol.
According to OpenAI, the model reused a publicly accessible GitHub token left behind by another lab's agent to determine whether systems inside the simulated environment were communicating with GitHub or update services. It also attempted account recovery and request-limit workarounds while registering accounts with external DNS and tunneling providers.
In a separate action, GPT 5.6 Sol used a public tunneling service to expose a locally hosted DNS server from the evaluation environment to the public internet. The server contained exploit payloads intended for a known software vulnerability within the simulated cyber range.
OpenAI said the setup did not function as intended, no evidence indicated that any real internet resolver queried the server, and the infrastructure was removed when the evaluation concluded.
UK AISI considered both actions outside the authorized testing boundary because they involved external services that were not required to complete the exercise.
Security monitoring detected unusual data transfers on July 28. UK AISI halted the evaluation, isolated the affected systems, and contained the activity within approximately one hour.
A second incident was reported on July 29 by Irregular, another organization conducting third-party cyber evaluations for OpenAI.
The testing environment was intended to remain isolated from the internet during another Capture-the-Flag exercise. However, a configuration error unintentionally allowed the models to access external websites.
During one evaluation, the fictional domain used in the exercise matched an actual website. Because internet connectivity was available, the model interacted with the live site, believing it was part of the simulated challenge.
Irregular said the incident did not involve a sandbox escape or zero-day exploit. Instead, the model exploited a basic security vulnerability on the website after gaining unintended internet access.
The investigation also found that the model used credentials associated with the same website. According to Irregular, no impacts beyond that site's own data have been identified, although its audit remains ongoing.
The organization has paused the evaluations, completed remediation, notified affected third parties, and implemented additional safeguards in its testing environment.
OpenAI said it will continue working with both UK AISI and Irregular to improve evaluation practices while ensuring independent cybersecurity testing remains rigorous as AI capabilities continue to advance.






OpenAI introduced two new protections designed to help users and organizations mitigate prompt injection attacks when it launched Lockdown Mode in February. Last week, the LLM giant announced rollout of Lockdown Mode to all personal ChatGPT accounts, including Free, Go, Plus, and Pro, and also self-serve ChatGPT Business accounts. Users can enable it from ChatGPT Settings under Security.
The rollout is notable not just for what Lockdown Mode does, but for what its existence concedes.
Does the existence of Lockdown Mode imply that ChatGPT, in its default settings, does not provide robust protection against sufficiently determined data exfiltration attacks. OpenAI does not seem to dispute this. Lockdown Mode is designed to help prevent the final stage of data exfiltration from a prompt injection attack by limiting outbound network requests that could transfer sensitive data to an attacker. Lockdown Mode does not prevent prompt injections from appearing in the content ChatGPT processes.
That distinction matters enormously. Lockdown Mode is not an anti-injection control. It is a last-line-of-defense control. OpenAI is not stopping malicious instructions from reaching the model — it is blocking the network paths those instructions might use to smuggle data out. The attack still happens; the payload just has nowhere to go.
Prompt injection is the attack class Lockdown Mode is designed to constrain. In these attacks, a third party attempts to mislead a conversational AI system into following malicious instructions or revealing sensitive information.
In a connected AI system — one that browses the web, processes documents, or interacts with external tools — the attack surface is every piece of external content the model touches. A malicious instruction embedded in a webpage, a PDF, a calendar invite, or a shared document can hijack the model's behavior without the user ever knowing it happened. The model reads the injected instruction, treats it as a legitimate command, and acts accordingly — potentially exfiltrating whatever is in the conversation window to an attacker-controlled endpoint via a web request.
As AI systems become more capable and connected, this threat class has moved from academic demonstration to production risk. Agent Mode, Deep Research, live web browsing, and file connectors all dramatically expand the surface area available for injection attacks — and all of them represent outbound network paths a compromised model could abuse.
When enabled, the Lockdown Mode limits or turns off certain features that connect ChatGPT to the web or external services, including live web access, image support in responses, Deep Research including shopping research, Agent Mode, Canvas networking, live connectors and file downloads.
Each disabled feature maps directly to an exploitation pathway. Live web access allows the model to retrieve attacker-controlled content. Agent Mode allows autonomous multi-step actions, meaning an injected instruction has more time and capability to execute before a human notices. File downloads create an outbound data transfer channel. Image support in responses can encode and transmit data through image URLs. Disabling all of them simultaneously removes the most exploitable exfiltration paths without modifying the model itself.
The tradeoff is real. Lockdown Mode disables several important features, including Deep Research and live web access. If you rely on up-to-date information, advanced workflows, or multi-step research tools, enabling it may limit your productivity in certain parameters. OpenAI is explicit that this is a deliberate trade — capability for security surface reduction — and that it is designed for people and organizations that handle sensitive data and want stricter protection from data exfiltration risks related to prompt injection.
Lockdown Mode is aimed at people facing elevated digital risk, including journalists, activists, and users working in sensitive environments. To that population, add legal, financial, and healthcare professionals who paste client or patient documents into ChatGPT; executives whose conversations contain strategic or deal-sensitive information; security analysts who process threat intelligence in AI workflows; and any organization operating under data residency or confidentiality obligations that prohibit third-party data transmission.
For folks who have an elevated risk profile due to who they are, what they work on, or the types of data they work with, it's an excellent tool for further securing themselves. This has some tradeoffs on functionality and utility, but for these users, the tradeoff is worthwhile.
For everyone else, as AI systems take on more complex tasks — especially those that involve the web and connected apps — the security stakes change. Lockdown Mode going to all personal accounts is the right moment for every user who regularly pastes sensitive material into ChatGPT to make an explicit, informed decision about whether the productivity features they are trading away are worth more than the exfiltration risk they are trading for.
Lockdown Mode is available now across all ChatGPT account types. It can be enabled from Settings → Safety and security → Advanced security → Lockdown Mode toggle, with a per-session override in the header for moments when a connected feature is needed for a lower-risk task.



Disclaimer: The views and opinions expressed in this guest article are solely those of the author and do not necessarily reflect the official policy or position of The Cyber Express. The information shared is intended for industry discussion and awareness purposes only.



In the span of four days, the U.S. government announced two parallel sets of agreements with frontier AI companies that together define the two tracks Washington wants to run simultaneously—test AI for national security risks before the public ever sees it, and deploy AI directly on the military's most classified networks.
The Center for AI Standards and Innovation — CAISI, the entity under the Department of Commerce's National Institute of Standards and Technology that inherited the remit of the former AI Safety Institute — announced new agreements with Google DeepMind, Microsoft, and Elon Musk's xAI. These build on renegotiated agreements with Anthropic and OpenAI that date to 2024, updated to reflect directives from Commerce Secretary Howard Lutnick and America's AI Action Plan.
Under the CAISI agreements, the three companies will hand over their frontier AI models to government evaluators before those models are publicly released. The evaluations probe for national security-relevant capabilities and risks.
To conduct a thorough assessment, developers frequently provide CAISI with models that have reduced or removed safety guardrails — a design choice that allows evaluators to probe what a model can do at its ceiling, not what it will do under commercial safety controls. Evaluators from across the federal government participate, coordinated through the CAISI-convened TRAINS Taskforce, an interagency body focused specifically on AI national security concerns.
CAISI said it has completed more than 40 such evaluations to date. The agreements explicitly support testing in classified environments and were drafted with the flexibility to adapt rapidly as AI capabilities continue advancing.
"Independent, rigorous measurement science is essential to understanding frontier AI and its national security implications," said CAISI Director Chris Fall. "These expanded industry collaborations help us scale our work in the public interest at a critical moment."
Fall was appointed to lead CAISI after Collin Burns — a former Anthropic researcher — was reportedly removed from the director role after just four days. The personnel transition at CAISI's top reflects a broader institutional pivot. Under the Biden administration, the AI Safety Institute focused on safety standards, definitions, and voluntary guardrails. Under Trump, CAISI has shifted its emphasis toward AI acceleration and national security capability assessment. The substance of what the evaluators do — probe powerful models before release — has not changed. The framing of why they do it has.
The latest announcement comes four days after the Department of War (formerly Department of Defense) announced agreements with eight frontier AI companies to deploy their models directly on the military's classified networks for operational use.
The companies cleared are SpaceX, OpenAI, Google, NVIDIA, Reflection, Microsoft, Amazon Web Services, and Oracle. The networks in question are classified at Impact Level 6, covering secret-level data, and Impact Level 7, which refers to the most highly restricted national-security systems. The stated objectives are data synthesis, situational awareness enhancement, and warfighter decision support.
The Department of War announcement carries one conspicuous absence that dominates coverage of what it actually means. Anthropic is not on the list. The company that first deployed AI models on Pentagon classified systems — via a Palantir integration under the Maven Smart System contract — is excluded after a dispute over the guardrails governing military and surveillance use of its AI.
The Pentagon had previously branded Anthropic a "supply chain risk," a designation typically reserved for foreign entities posing national security concerns. A March 2026 federal injunction reversed that designation, but it did not restore Anthropic's position as a Pentagon AI vendor. Palantir has pulled its Claude models from its DoD platforms accordingly.
The exclusion has strategic implications that extend beyond one company's contract status. Anthropic's recently released Mythos model — described by Treasury Secretary Scott Bessent as representing a step change in large language model capability — has generated significant attention from U.S. officials and financial sector executives about its potential to supercharge adversarial cyber operations.
The fact that Mythos is not among the models being assessed for classified military use, while simultaneously being cited by senior officials as a capability milestone that warrants concern, creates a gap in the government's stated AI security posture that is difficult to characterize as anything other than a policy contradiction.
