PT-2026-102350 · Pypi · Pyjwt
CVSS v3.1
7.4
High
| Vector | AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
Name of the Vulnerable Software and Affected Versions
PyJWT versions 2.13.0 through 2.13.x
Description
The
HMACAlgorithm.from jwk() function is affected because the PyJWK verification path uses the decoded key without applying prepare key validation. This occurs when a trusted JSON Web Key (JWK) Set contains an oct entry with an empty k variable. An attacker can sign an HMAC token using a zero-length key, allowing forged tokens to carry arbitrary authenticated claims.Recommendations
Update to version 2.14.0.
Exploit
Fix
Improper Verification of Cryptographic Signature
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Weakness Enumeration
Related Identifiers
Affected Products
Pyjwt