{"id":"CVE-2026-57175","aliases":["GHSA-vq6g-g6c7-5f2j","PYSEC-2026-4167"],"url":"https://o3.security/vulnerability/CVE-2026-57175","summary":"social-auth-core has an Improper Authentication issue","details":"### Impact\n\nThe SAML backend accepted SAML responses on the Assertion Consumer Service endpoint without verifying that they matched a previously issued `AuthnRequest`.\n\nApplications using SAML account association could allow an attacker with a valid account on a trusted IdP to link the attacker's SAML identity to a logged-in victim's local account. The attacker could then authenticate through SAML and gain access to the victim's account.\n\nThe issue affects applications using the SAML backend together with authenticated account association.\n\n### Patches\n\nThe issue has been fixed by validating SAML responses against stored `AuthnRequest` IDs.\n\nUsers should upgrade to a patched version.\n\nFix:\n\n* https://github.com/python-social-auth/social-core/pull/1794\n\n### Workarounds\n\nApplications that cannot upgrade immediately should disable SAML account association for already authenticated users.\n\nIf SAML login is not required, the SAML backend can also be disabled by removing it from `SOCIAL_AUTH_AUTHENTICATION_BACKENDS`.\n\nThere is no complete workaround while continuing to allow vulnerable SAML account association.\n\n### Credits\n\nReported through GitHub private vulnerability reporting by Liyi Zhou, Ziyue Wang, Strick, Maurice, and Chenchen Yu from the University of Sydney security research team.\n\nReporter references:\n\n* https://lzhou1110.github.io/\n* https://zyy0530.github.io/\n* https://str1ckl4nd.github.io/\n* https://maurice.busystar.org/\n* https://7thparkk.github.io/","published":"2026-09-24T17:11:49.925Z","modified":"2026-10-21T02:58:44.718271996Z","cvss":{"score":6.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"social-auth-core","fixedVersion":"5.0.0"}],"fix":{"url":"https://github.com/python-social-auth/social-core/pull/1794","label":"python-social-auth/social-core#1794"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57175.json"},{"type":"ADVISORY","url":"https://github.com/python-social-auth/social-core/security/advisories/GHSA-vq6g-g6c7-5f2j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57175"},{"type":"WEB","url":"https://github.com/python-social-auth/social-core/pull/1794"},{"type":"WEB","url":"https://github.com/python-social-auth/social-core/commit/5c72f71125bc60e4411f09e2a9f998de5da7fcb6"},{"type":"PACKAGE","url":"https://github.com/python-social-auth/social-core"},{"type":"WEB","url":"https://github.com/python-social-auth/social-core/releases/tag/5.0.0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:58:44.718271996Z"}}