Claude Mythos finds a 27 year about bug!

SCWorld.com reported that “Mythos Preview identified decades-old bugs, including a 27-year-old integer overflow flaw in OpenBSD and a 16-year-old out-of-bounds write flaw in FFmpeg, demonstrating the model’s ability to find new flaws in code that was heavily scrutinized for years.”  The April 9, 2026 article entitled "Claude Mythos Preview identifies 27-year-old bug, finds ‘thousands’ of zero-days in weeks” (https://tinyurl.com/2878ynwy) included these comments:

Anthropic said Feb. 7 that Claude Mythos Preview, its new large language model (LLM), discovered “thousands” of severe zero-day vulnerabilities in both open and closed-source software in a matter of weeks.

The company's Red Team said what sets Mythos Preview apart is its ability to develop novel exploits for vulnerabilities with little to no human intervention, sometimes even "overnight."

These companies include Amazon Web Services (AWS), Apple, Broadcom, Cisco, CrowdStrike, Google, JPMorganChase, the Linux Foundation, Microsoft, NVIDIA, and Palo Alto Networks.

“Our foundational work with these models has shown we can identify and fix security vulnerabilities across hardware and software at a pace and scale previously impossible,” said Anthony Grieco, senior vice president and chief security and trust officer at Cisco. “That's a profound shift, and a clear signal that the old ways of hardening systems are no longer sufficient.”

An in-depth blog post from the Anthropic Red Team offers further detail about how Mythos Preview discovered new vulnerabilities and developed zero-day exploits and N-day exploits – exploits for previously discovered vulnerabilities for which many systems may remain unpatched.

The Red Team researchers said once armed with tools, scaffolds and prompts, as well as Claude Code, Mythos Preview could discover these vulnerabilities and develop exploits with no human intervention after the prompt. In some cases, it autonomously chained together several vulnerabilities to achieve a successful exploit.

Very good and bad news!