Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.
VOLERION
Volerion Security Research

NOT DEFERRED DATABASE

VULNERABILITIES

CVE-2026-102266 Details

Description

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.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:7.4 HIGHVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URLSource(s)Tag(s)
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r CISA-ADP
https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934c [email protected]
https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 [email protected]
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r [email protected]

Weakness Enumeration

CWE-IDCWE NameSource
CWE-347Improper Verification of Cryptographic Signature[email protected]

Affected Products

No affected product data is available for this CVE.

Change History

2 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-102266
NVD Published Date:
Sep 28, 2026
NVD Last Modified:
Sep 30, 2026
Source:
[email protected]
CVE-2026-102266 Details - Not Deferred