Bug 2542685 (CVE-2026-102268) - CVE-2026-102268 pyjwt: PyJWT: Authentication bypass via improper public key validation
Summary: CVE-2026-102268 pyjwt: PyJWT: Authentication bypass via improper public key v...
Keywords:
Status: NEW
Alias: CVE-2026-102268
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
urgent
urgent
Target Milestone: ---
Assignee: Product Security DevOps Team
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Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-28 20:46 UTC by OSIDB Bzimport
Modified: 2026-10-19 20:47 UTC (History)
112 users (show)

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Description OSIDB Bzimport 2026-09-28 20:46:02 UTC 
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.
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