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{"bugzilla": {"description": "joserfc: joserfc: Issuer-validation bypass via array-valued claims", "id": "2523102", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2523102"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N", "status": "draft"}, "cwe": "CWE-480", "details": ["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.", "A flaw was found in joserfc, a Python library for JSON Object Signing and Encryption (JOSE) standards. A remote attacker could exploit a vulnerability in the JWTClaimsRegistry by crafting a JSON Web Token (JWT) with an array-valued issuer (iss) claim. This flaw allows the attacker to bypass the intended issuer validation, potentially leading to impersonation or unauthorized access."], "name": "CVE-2026-75509", "package_state": [{"cpe": "cpe:/a:redhat:lightspeed_core", "fix_state": "Fix deferred", "package_name": "lightspeed-core/lightspeed-stack-rhel9", "product_name": "Lightspeed Core"}, {"cpe": "cpe:/a:redhat:migration_toolkit_applications:8", "fix_state": "Fix deferred", "package_name": "mta/mta-solution-server-rhel9", "product_name": "Migration Toolkit for Applications 8"}, {"cpe": "cpe:/a:redhat:openshift_lightspeed", "fix_state": "Fix deferred", "package_name": "openshift-lightspeed/lightspeed-agentic-sandbox-rhel9", "product_name": "OpenShift Lightspeed"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Fix deferred", "package_name": "ansible-automation-platform-26/lightspeed-chatbot-rhel9", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Fix deferred", "package_name": "ansible-automation-platform-27/lightspeed-chatbot-rhel9", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:rhel_cla:1", "fix_state": "Fix deferred", "package_name": "rhel-cla/rhel-knowledge-bridge-rhel10", "product_name": "Red Hat Enterprise Linux command line assistant"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "jaeger", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:container_native_virtualization:4", "fix_state": "Fix deferred", "package_name": "container-native-virtualization/ocp-virt-validation-checkup-rhel9", "product_name": "Red Hat OpenShift Virtualization 4"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Fix deferred", "package_name": "satellite/foreman-mcp-server-rhel9", "product_name": "Red Hat Satellite 6"}], "public_date": "2026-08-24T20:08:07Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-75509\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-75509\nhttps://github.com/authlib/joserfc/commit/76ee6a59bf5773c0af00b99076c5e199031f97f1\nhttps://github.com/authlib/joserfc/security/advisories/GHSA-r74j-q665-7rpj"], "threat_severity": "Moderate"}