CVE-2026-102266

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from_jwk is affected because PyJWK verification path used the decoded key without applying prepare_key validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As a result, an attacker signs an HMAC token with the same zero-length key accepted by PyJWT. Consequently, forged token can carry arbitrary authenticated claims. This issue is fixed in version 2.14.0.
Configurations

Configuration 1 (hide)

cpe:2.3:a:pyjwt_project:pyjwt:2.13.0:*:*:*:*:*:*:*

History

07 Oct 2026, 20:55

Type Values Removed Values Added
First Time Pyjwt Project pyjwt
Pyjwt Project
References () https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934c - () https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934c - Patch
References () https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 - () https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 - Product, Release Notes
References () https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r - () https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r - Exploit, Vendor Advisory
CPE cpe:2.3:a:pyjwt_project:pyjwt:2.13.0:*:*:*:*:*:*:*

29 Sep 2026, 20:17

Type Values Removed Values Added
References () https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r - () https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r -

28 Sep 2026, 21:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-09-28 21:17

Updated : 2026-10-07 20:55


NVD link : CVE-2026-102266

Mitre link : CVE-2026-102266

CVE.ORG link : CVE-2026-102266


JSON object : View

Products Affected

pyjwt_project

  • pyjwt
CWE
CWE-347

Improper Verification of Cryptographic Signature