CVE-2026-34950
CRITICAL
NVD
CVSS Score
9.1
Severity
CRITICAL
Published
Apr 06, 2026
Vendor
unknown
Description
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.