CVE-2026-75509
MEDIUM
NVD
CVSS Score
6.5
Severity
MEDIUM
Published
Aug 24, 2026
Vendor
unknown
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.