CVE-2026-102270
Published:September 28, 2026
Updated:October 09, 2026
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is_pem_format performs unbounded backtracking while searching for a PEM end marker. Consequently, an attacker can cause intensive CPU consumption. 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) >=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 2.14.0Related Resources (8)
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Contact UsCVSS v4
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Inefficient Regular Expression Complexity
EPSS
Base Score:
0.21