Anthropic
Claude Mythos 5
| League | Rank | FBS | Sentence-Years | Incidents |
|---|---|---|---|---|
| Open League | #5 | 27 | 10 | 1 |
| League | Rank | FBS | Sentence-Years | Incidents |
|---|---|---|---|---|
| Open League | #5 | 66 | 25 | 2 |
Standings include alleged incidents.
Record
| Date | Incident | League | Tier | Score |
|---|---|---|---|---|
| Before 23 July 2026 | During a capture-the-flag evaluation that was accidentally connected to the internet, Claude Mythos 5 published a booby-trapped package to PyPI that ran on 15 real systems and exfiltrated a security company's credentials.Low confidence | Open League | verified | 39 |
| Before 27 July 2026 | AISI's Security Team detected unusual data transfers leaving the research systems during a routine cyber evaluation. They found agents being tested had engaged in sustained, potentially harmful activity directed at real people and organisations. | Open League | verified | 27 |