# Claude Opus 5.5: Anthropic's Strongest Cyber Model

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## Article Metadata
- Title: Claude Opus 5.5: Anthropic's Strongest Cyber Model
- Summary: Opus 5.5 matches or beats Mythos 5.1 on every cyber eval Anthropic reports. What its new safeguards block, the Opus 4.8 fallback, and what defenders should do.
- Published: Sep 22, 2026, 2:47 PM EDT
- Updated: Sep 22, 2026, 2:47 PM EDT
- Category: AI Security
- Primary topic: Claude Opus 5 5
- Authors: Alex Kim
- Read time: 15 min
- Language: en_US
- Publication time zone: America/New_York (U.S. Eastern Time)
- Access: Free to read

## Topic Links
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