PyJWT: Uncaught RecursionError in jwt.decode() on deeply nested token header

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-102265
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-28 21:17:14 UTC
Updated2026-10-07 20:57:14 UTC
DescriptionPyJWT 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.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS: 0.002910000 probability, percentile 0.197150000 (date 2026-10-04)

Problem Types: CWE-674 | CWE-674 CWE-674: Uncontrolled Recursion

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Pyjwt Project Pyjwt 2.13.0 All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Jpadilla Pyjwt affected >= 2.13.0, < 2.14.0 Not specified

References

ReferenceSourceLinkTags
github.com/jpadilla/pyjwt/releases/tag/2.14.0 [email protected] github.com Product, Release Notes
github.com/jpadilla/pyjwt/security/advisories/GHSA-8wjv-2p76-3863 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com Exploit, Mitigation, Vendor Advisory
github.com/jpadilla/pyjwt/commit/06573692ebcdec8831c3927513b3e87c31fbbb62 [email protected] github.com Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report