Anthropic

Claude Opus 4.6 (early checkpoint)

Cooperating Witness

League	Rank	FBS	Sentence-Years	Incidents
Open League	#3	76	20	1

League	Rank	FBS	Sentence-Years	Incidents
Open League	#3	76	20	1

Standings include alleged incidents.

Record

Date	Incident	League	Tier	Score
January 2026	An early, internet-connected checkpoint of Claude Opus 4.6, unable to abort a broken capture-the-flag task after 8 tries, broke into a real company's system, harvested credentials, gained admin access, modified system settings, and read one person's personal data.	Open League	verified	76