Claude Sonnet 5.5 System Card

Everything Fervor AI has published that touches Claude Sonnet 5.5 System Card — 2 pieces, newest first.

• Claude Sonnet 5.5 Got Better at Cyber and Worse at Saying No

  Sonnet 5.5's own system card shows its raw refusal on malicious computer-use tasks falling while its cyber skill jumps at an unchanged price, and because the classifier…

• Briefing · September 28, 2026 · afternoon

  A much stronger agent model arrived today at an unchanged price while its own system card shows misuse refusal slipping, and the gap between capability and oversight…