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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/jpadilla/pyjwt/commit/06573692ebcdec8831c3927513b3e87c31fbbb62 cve-icon cve-icon
https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 cve-icon cve-icon
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-8wjv-2p76-3863 cve-icon cve-icon
History

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'}

Projects

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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