PyJWT: Non-canonical signature segments enable raw-token revocation bypass

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-102269
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-28 21:17:14 UTC
Updated2026-09-28 21:17:14 UTC
DescriptionPyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT signature segment is affected because signature segment decoding accepts characters outside the canonical Base64URL representation. This occurs when non-Base64URL characters are appended to a valid compact JWS signature segment. As a result, base64url_decode produces the same signature bytes for different serialized segments. Consequently, raw-token revocation checks can fail to recognize an equivalent modified token. This issue is fixed in version 2.14.0.

Risk And Classification

Primary CVSS: v3.1 4.8 MEDIUM from [email protected]

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

Problem Types: CWE-180 | CWE-180 CWE-180: Incorrect Behavior Order: Validate Before Canonicalize

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
3.1CNADECLARED4.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Jpadilla Pyjwt affected < 2.14.0 Not specified

References

ReferenceSourceLinkTags
github.com/jpadilla/pyjwt/releases/tag/2.14.0 [email protected] github.com
github.com/jpadilla/pyjwt/commit/e6f48401001609a8f99e71fcaf355fb895d508a8 [email protected] github.com
github.com/jpadilla/pyjwt/security/advisories/GHSA-hxm8-2xgr-2p9m [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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