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Anthropic
Claude Opus 4.6 (early checkpoint)
Cooperating Witness
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