{"apiVersion":"1.0","identifier":"CVE-2026-75509","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.","publishedAt":"2026-08-24T20:17:19","lastModifiedAt":"2026-08-25T17:18:16","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-75509","cvssScore":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N","epssProbability":0.00091,"riskScore":0.66,"affectedProduct":"joserfc","affectedVersions":"<1.7.3","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-75509","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-75509","en":"https://www.redsauce.net/en/cves/CVE-2026-75509","fr":"https://www.redsauce.net/fr/cves/CVE-2026-75509","pt":"https://www.redsauce.net/pt/cves/CVE-2026-75509","de":"https://www.redsauce.net/de/cves/CVE-2026-75509","sk":"https://www.redsauce.net/sk/cves/CVE-2026-75509","el":"https://www.redsauce.net/el/cves/CVE-2026-75509"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-75509"}}