CVE-2026-102268
Published:September 28, 2026
Updated:October 09, 2026
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.
Affected Packages
pyjwt (CONDA):
Affected version(s) >=1.4.0 <2.14.0Fix Suggestion:
Update to version 2.14.0pyjwt (CONDA):
Affected version(s) >=2.4.0 <2.14.0Fix Suggestion:
Update to version 2.14.0https://github.com/jpadilla/pyjwt.git (GITHUB):
Affected version(s) >=2.4.0 <2.14.0Fix Suggestion:
Update to version 2.14.0pyjwt (PYTHON):
Affected version(s) >=0.1.1 <2.14.0Fix Suggestion:
Update to version 2.14.0pyjwt (PYTHON):
Affected version(s) >=2.4.0 <2.14.0Fix Suggestion:
Update to version 2.14.0Related Resources (8)
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Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Verification of Cryptographic Signature
EPSS
Base Score:
0.20