joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to version 1.7.3, JWTClaimsRegistry applies membership matching to list-valued iss and sub claims, allowing an array-valued iss that contains the expected issuer to pass an intended equality check and enabling issuer-validation bypass. This issue is fixed in version 1.7.3.

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History

Wed, 26 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 25 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
First Time appeared Authlib
Authlib joserfc
Vendors & Products Authlib
Authlib joserfc

Mon, 24 Aug 2026 20:15:00 +0000

Type Values Removed Values Added
Description joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to version 1.7.3, JWTClaimsRegistry applies membership matching to list-valued iss and sub claims, allowing an array-valued iss that contains the expected issuer to pass an intended equality check and enabling issuer-validation bypass. This issue is fixed in version 1.7.3.
Title joserfc claim-validation bypass via array-typed single-string claims (iss/sub/jti)
Weaknesses CWE-290
CWE-345
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-25T16:42:19.769Z

Reserved: 2026-08-17T20:49:21.598Z

Link: CVE-2026-75509

cve-icon Vulnrichment

Updated: 2026-08-25T16:41:50.456Z

cve-icon NVD

Status : Received

Published: 2026-08-24T20:17:19.183

Modified: 2026-08-25T17:18:16.470

Link: CVE-2026-75509

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-25T00:00:04Z

Weaknesses