CVE-2026-102266
HIGHCVSS 7.4Description
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.
Timeline
Published:September 28th, 2026 9:17 PM
Last modified:October 7th, 2026 8:55 PM
CVSS Scoring
CVSS v3: 7.4 (HIGH)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected Software
From NVD CPE configuration data
Vendors
pyjwt_project
Products
pyjwt
Weaknesses (CWE)
References & Reports
Advisories, patches, and third-party reports
- https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934cPatch
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0Product
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3rExploit
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3rExploit
Source: NIST NVD · Data may lag official sources by up to one minute