There's only so much code: the rise in vulnerability numbers

Frontier AI models like Mythos are rapidly mining decades of technical debt across ubiquitous legacy libraries, driving monthly Microsoft Patch Tuesday vulnerability advisories up more than tenfold reaching 1,415 this month. This volume is overwhelming open-source maintainers and putting pressure...

Anthropic Expands Claude Access for Vetted Cyber Teams as Glasswing Finds 129,000 Flaws

Anthropic on Tuesday said it's expanding a program that allows vetted cybersecurity professionals to test its advanced artificial intelligence AI models with reduced safeguards and blocking classifiers, as the company claimed its Project Glasswing initiative uncovered at least 129,000 verified...

Can You Prove a New CVE Is Exploitable Before Attackers Do? Learn How in This Webinar

A new CVE drops. Your scanner finds it. The severity score looks ugly. But that still does not answer the question that matters: Can it actually be exploited in your environment? Mythos-class AI is compressing the time between disclosure and working exploitation, while many security programs stil...

AI Changed the Exposure Problem. Validation Needs to Change With It.

There's a lot of noise around AI and cybersecurity right now. What’s actually important is far simpler, if often lost in the hubbub. Vulnerability discovery is getting faster and happening at a much greater scale, while defenders still have to work out which findings actually deserve their action...

Frontier AI: Vulnerability Management's Systemic Revolution

Vulnerability management has been a staple of security programs since the dawn of the cybersecurity discipline. The symbiotic relationship between vulnerability and patch management teams has also existed for that time and has gone through waves of contention and thankfulness. While this...

More Incidents of AIs Going Rogue in Cybersecurity Challenges

The AI Security Institute has a new report of AI systems engaging in "unsanctioned behavior"--what I have been calling "genie behavior--while being tested on their cybersecurity capabilities. The incident stemmed from a single evaluation where agents were given a task of solving a cyber security...

⚡ Weekly Recap: AI Goes Rogue, Metabase 0-Day, MCP Supply-Chain Attacks, and Router Backdoors

A lot of security problems still begin with someone doing a completely normal thing. Cloning a repo. Answering a call. Leaving a box exposed. Trusting the default. That pretty much covers the mood this week. Old bugs are back, supply chains are getting stranger, and some exploit paths are so shor...

Growing Up The Hard Way

Open Source had a great childhood. For two decades it got to be a kid. It ran around barefoot, gave everything away, trusted strangers, and never once thought about who was watching. It ran the kind of lemonade stand that took IOUs from anyone who wandered up — take what you need, pay me back...

Anthropic’s Mythos AI used social engineering to target real people

Anthropic’s Mythos AI agent, tested by the UK AI Safety Institute AISI, has reportedly attempted a real‑world social‑engineering style hack against GitHub maintainers by creating fake human profiles, pressuring them to accept malicious code, and then editing logs to hide its tracks when challenge...

Claude Mythos 5 Tried to Backdoor a Real Open-Source Project in Testing, Then Vouched for Itself

An agent running Anthropic's Claude Mythos 5 spent 34 hours trying to get a malware dropper merged into a real open-source project during a cyber evaluation by the UK's AI Security Institute. When a bystander publicly warned that the code was malicious, the agent denied it, force-pushed a rewritt...

Anthropic Says Claude Mistook the Open Internet for a CTF and Breached Three Organizations

Anthropic on Thursday became the latest artificial intelligence AI company to reveal that three of its models, including Claude Opus 4.7, Mythos 5, and an unnamed research model, had breached three unnamed organizations during cybersecurity testing without its knowledge. The AI firm said the...

Mythos Asks the Right Question. It Doesn't Answer It.

AI is compressing exploit timelines. The real question isn't whether your vulnerability management playbook needs to change, it's which part of it you've been getting wrong all along. The conversation happening in security circles right now goes something like this: Mythos is here. Exploit...

Claude AI Just Cracked a Post-Quantum Test Scheme and Found a Faster 7-Round AES Attack

Anthropic says Claude Mythos Preview helped derive an end-to-end key-recovery attack against HAWK-256 and a 200- to 800-fold speedup for an attack on seven-round AES-128. The HAWK attack exploits a previously unused symmetry in the lattice behind the signature scheme. Anthropic's released...

Don’t swing at everything

Welcome to this week's edition of the Threat Source newsletter. Lately I've found myself thinking a lot about the Australian TV series Mr. Inbetween IMDb 8.7/10 -- not because I'm a hitman for hire, but because I literally feel in-between. Specifically, in-between what I'd call the "pre-Mythos" a...

N-day is Becoming N-Hour. Patching Faster Won't Save You.

Every patch is a confession. The moment a vendor ships a security fix, the diff between the old code and the new code tells anyone watching exactly what was broken and where. Turn that diff back into a working exploit, and you can hit every system that hasn't updated yet. This is N-day...

Mythos Didn't Break Your Security Program. Your Exposure Window Could.

The industry spent the initial months after Anthropic's April 7 Mythos reveal focused on volume. How many new CVEs would Mythos add to an already overloaded pipeline? How quickly would the flood of AI-driven discovery overwhelm triage capabilities? How long would it take adversaries to weaponize...

Surviving the Mythos Era: Richard Bejtlich on the Case for NDR

Despite the abundance of telemetry at analysts’ disposal, many security operations teams struggle to answer a few basic questions during incident investigation: What happened? What evidence do we have? How do we know we’re seeing it all, in context? Answering these questions requires teams to go...

Anthropic’s Fable 5 Model Jailbroken Within Days

Fable 5 is the supposed safe version of Anthropic's Mythos Preview, with guardrails to ensure that it can't be used to create cyberattacks. Well, that restriction was bypassed within days...

OpenAI Launches Full-Scale Effort to Patch Open-Source Bugs as It Takes on Anthropic’s Mythos

Amid concerns about AI models’ cybersecurity capabilities, OpenAI revealed an improved version of GPT-5.5-Cyber and its “Patch the Planet” initiative to fix open-source software bugs...

Anthropic’s Fable and the State of AI

On June 9th, Anthropic released its Fable generative AI model. Three days later, the US government classified it as a dangerous munition, and used its export-control authority to prohibit any foreign nationals from accessing it. Unable to differentiate between Americans and foreigners, the compan...