CVE-2026-101918

PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b	Patch
https://github.com/jpadilla/pyjwt/releases/tag/2.15.0	Product Release Notes
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*

History

07 Oct 2026, 20:59

Type	Values Removed	Values Added
References	~~() https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b -~~	() https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b - Patch
References	~~() https://github.com/jpadilla/pyjwt/releases/tag/2.15.0 -~~	() https://github.com/jpadilla/pyjwt/releases/tag/2.15.0 - Product, Release Notes
References	~~() https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v -~~	() https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v - Exploit, Mitigation, Vendor Advisory
First Time		Pyjwt Project pyjwt Pyjwt Project
CPE		cpe:2.3:a:pyjwt_project:pyjwt::::::::

28 Sep 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-28 21:17

Updated : 2026-10-07 20:59

NVD link : CVE-2026-101918

Mitre link : CVE-2026-101918

CVE.ORG link : CVE-2026-101918

JSON object : View

Products Affected

pyjwt_project

pyjwt

CWE

CWE-248

Uncaught Exception

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