Exclusive: Anthropic is testing ‘Mythos,’ its ‘most powerful AI model ever

One of the eye-catching claims is that it found a 27-year-old vulnerability in OpenBSD, which, if I’ve understood correctly, would be the third one in its history.

red.anthropic.com

Claude Mythos Preview \ red.anthropic.com

https://ftp.openbsd.org/pub/OpenBSD/patches/7.8/common/025_sack.patch.sig

That was patched 25 March 2026, but no mention of this in the OpenBSD journal:

undeadly.org

OpenBSD Journal: A resource for the OpenBSD community

(Netflix and Sony Playstation, among others, use OpenBSD).