CVE-2026-34950
fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in fast-
fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in fast-jwt/src/crypto.js uses a ^ anchor that is defeated by any leading whitespace in the key string, re-enabling the exact same JWT algorithm confusion attack that CVE-2023-48223 patched.
CRITICAL · CVSS 9.1
EPSS 0.00025
Act now
- Public exploit or PoC is available
- SSVC automatable: yes - attacks can be scripted at scale
- CVSS base score ≥ 7.0
Sigma rules0
YARA rules0