CVE-2026-102272
7.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Summary
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 Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| jpadilla | pyjwt | >= 2.13.0, < 2.14.0 | affected |
Weaknesses
- CWE-347: CWE-347: Improper Verification of Cryptographic Signature
References
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947
- https://github.com/jpadilla/pyjwt/commit/180783930de91876bc0d601f826a1f2956057291
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0
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