CVE-2026-102268
criticalPyJWT is a Python implementation of JSON Web Token standards.
Vendor / product: Pyjwt Project — pyjwt
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07 security-advisories@github.com
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 security-advisories@github.com
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9 security-advisories@github.com
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9 134c704f-9b21-4f2e-91b3-4a467353bcc0