# Anthropic website hints at Claude Mythos 5.5 for cybersecurity and biology

> Original title: BREAKING 🔥: A hidden Claude Mythos 5.5 mention has been spotted on the official Anthropic website.

- Source: Testing Catalog
- Published: 2026-11-01T15:31:18.000Z
- Bad Influence: https://badinfluence.news/items/cba0iptlmh9hfxwwevmh1tbt5
- Original: https://x.com/testingcatalog/status/2116915996850074008

## Summary

A mention of "Claude Mythos 5.5" was spotted on Anthropic's official website, described as "our most capable model class for cybersecurity and biology research." Testing Catalog speculates a Mythos 5.5 cyber-defense release could come next week, with Fable 5.5 possibly following, but this remains unconfirmed.

## Post

BREAKING 🔥: A hidden Claude Mythos 5.5 mention has been spotted on the official Anthropic website. 

> "Claude Mythos 5.5 - Our most capable model class for cybersecurity and biology research."

Should we expect Mythos 5.5 for cyber defense next week? Fable 5.5 may come along as well (speculation). 

Soon? 👀

![](https://badinfluence.news/api/img-proxy?u=https%3A%2F%2Fpbs.twimg.com%2Fmedia%2FHWDL3VTWUAAX560.jpg&mode=thumb&exp=1793836800&sig=0a98eb74955effba)

## Quoted post @kimmonismus

> Mythos 5.5 is already listed HTML source code of Anthropic's official website
> 
> Thanks to the anonymous person who sent me the tip via email :)

https://x.com/kimmonismus/status/2116914141017370972