{"schemaVersion":3,"id":"CVE-2026-75509","aliases":["UBUNTU-CVE-2026-75509","DEBIAN-CVE-2026-75509"],"status":"published","duplicateOf":null,"title":null,"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. 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