CVEvulnerability
CVE-2026-102272
7.4 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-09-28
- Last modified
- 2026-10-06
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 7.4 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-347
Description
PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.prepare_key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with a UTF-8 BOM and used in a mixed-algorithm verification path. As a result, public JWK bypasses asymmetric-key detection and becomes the HMAC secret. Consequently, an attacker who knows the public key can forge authenticated tokens. This issue is fixed in version 2.14.0.
Affected configurations
• pyjwt project pyjwt 2.13.0
Related
Weakness · CWE (1)
- CWE-347 Improper Verification of Cryptographic Signature weakness
References
- https://github.com/jpadilla/pyjwt/commit/180783930de91876bc0d601f826a1f2956057291 Patch
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 Product, Release Notes
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947 Exploit, Mitigation, Vendor Advisory
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947 Exploit, Mitigation, Vendor Advisory