{"id":"CVE-2026-75509","title":"joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards","summary":"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…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N","cwe":["CWE-290","CWE-345","CWE-480"],"published":"2026-08-24","updated":"2026-10-12","sourceUpdated":"2026-10-12T15:10:00.207","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-75509","references":[{"url":"https://github.com/authlib/joserfc/commit/76ee6a59bf5773c0af00b99076c5e199031f97f1","label":"security-advisories@github.com"},{"url":"https://github.com/authlib/joserfc/security/advisories/GHSA-r74j-q665-7rpj","label":"security-advisories@github.com"},{"url":"https://github.com/authlib/joserfc/security/advisories/GHSA-r74j-q665-7rpj","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-75509.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-75509"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2523102"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-75509"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75509"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00124,"epssPercentile":0.02126,"ingestedAt":"2026-09-09T21:22:45.549Z","vendor":"Red Hat","product":"Red Hat Ansible Automation Platform 2","affected":["lightspeed_core","migration_toolkit_for_applications 8","openshift_lightspeed","ansible_automation_platform 2","enterprise_linux_command_line_assistant","openshift_virtualization 4","satellite 6"],"slug":"CVE-2026-75509","body":"## Overview\n\njoserfc 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Lightspeed Core, Migration Toolkit for Applications 8, OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, Red Hat Enterprise Linux command line assistant, Red Hat OpenShift Virtualization 4, … · no fix planned: Lightspeed Core, Migration Toolkit for Applications 8, OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, … · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-75509.json)","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}