CVE-2026-102271

Description

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.

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Produits concernés

• jpadilla pyjwt
• Pyjwt project pyjwt

Scores CVSS

Faiblesses (CWE)

• CWE-347

Références

• https://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499 Patch
• https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 ProductRelease Notes
• https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773 ExploitPatchVendor Advisory
• https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773 ExploitPatchVendor Advisory

Ailleurs

• NVD
• CVE.org
• CIRCL Vulnerability-Lookup
• CERT-FR
• GitHub Advisories