PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWS._load in jwt/api_jws.py is affected because parser catches ValueError but not RecursionError. This occurs when a deeply nested token header reaches json.loads. As a result, RecursionError escapes the documented PyJWT error hierarchy. Consequently, an unauthenticated malformed token can cause a request-level failure and HTTP 500. This issue is fixed in version 2.14.0.

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Mon, 28 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
Description PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWS._load in jwt/api_jws.py is affected because parser catches ValueError but not RecursionError. This occurs when a deeply nested token header reaches json.loads. As a result, RecursionError escapes the documented PyJWT error hierarchy. Consequently, an unauthenticated malformed token can cause a request-level failure and HTTP 500. This issue is fixed in version 2.14.0.
Title PyJWT: Uncaught RecursionError in jwt.decode() on deeply nested token header
Weaknesses CWE-674
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-28T20:48:04.664Z

Reserved: 2026-09-28T20:11:16.658Z

Link: CVE-2026-102265

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-28T21:17:14.077

Modified: 2026-09-28T21:17:14.077

Link: CVE-2026-102265

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-28T22:30:08Z

Weaknesses