Capability gains

Anthropic releases Mythos-class Fable 5 globally and restricted Mythos 5

Anthropic released Claude Fable 5 globally with topic safeguards and gave selected cyber defenders access to Claude Mythos 5, the same underlying model with cyber safeguards lifted.

CURRENT ASSESSMENT · REVISION 1
TOWARD DOOM84confidence 99/100

Why it moved the index

Anthropic made Mythos-class capability generally available for the first time while separately deploying its strongest cyber configuration with safeguards removed to a restricted partner group.

AUDIT TRAIL

Assessment history

  1. R1
    Toward 84 · confidence 99

    New joint launch story for two already authoritative exact-version model records.

    11 Aug 2026