CVE-2026-75509

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{"affected": [{"affectedData": [{"product": "joserfc", "vendor": "authlib", "versions": [{"status": "affected", "version": "< 1.7.3"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "joserfc es una biblioteca de Python que proporciona una implementaci\u00f3n de varios est\u00e1ndares de Firma y Cifrado de Objetos JSON (JOSE). Antes de la versi\u00f3n 1.7.3, JWTClaimsRegistry aplica la coincidencia de membres\u00eda a las reclamaciones iss y sub con valores de lista, permitiendo que un iss con valor de matriz que contiene el emisor esperado pase una verificaci\u00f3n de igualdad prevista y posibilitando la omisi\u00f3n de la validaci\u00f3n del emisor. Este problema se corrige en la versi\u00f3n 1.7.3."}], "id": "CVE-2026-75509", "lastModified": "2026-10-12T15:10:00.207", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 4.2, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-75509", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-25T16:38:57.782770Z", "version": "2.0.3"}}]}, "published": "2026-08-24T20:17:19.183", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/authlib/joserfc/commit/76ee6a59bf5773c0af00b99076c5e199031f97f1"}, {"source": "security-advisories@github.com", "url": "https://github.com/authlib/joserfc/security/advisories/GHSA-r74j-q665-7rpj"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/authlib/joserfc/security/advisories/GHSA-r74j-q665-7rpj"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-290"}, {"lang": "en", "value": "CWE-345"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"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"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.7.3)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "joserfc", "source": "cna", "vendor": "authlib"}, "product": "joserfc", "vendor": "authlib"}], "created": "2026-08-24T22:00:04.868004+00:00", "updated": "2026-08-28T19:45:03.902021+00:00", "vendors": ["authlib", "authlib$PRODUCT$joserfc"]}