CVE-2026-34950
CVE-2026-34950
9.1
CriticalPublished:
Last updated:
Source:security-advisories@github.com
Analyzed
Weakness (CWE)
CVSS Vector
v3.1- Attack Vector
- Network
- Attack Complexity
- Low
- Privileges Required
- None
- User Interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
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.
References
security-advisories@github.com
https://github.com/nearform/fast-jwt/security/advisories/GHSA-mvf2-f6gm-w987