{"id":"CVE-2025-27773","aliases":["GHSA-46r4-f8gj-xg56"],"url":"https://o3.security/vulnerability/CVE-2025-27773","summary":"SimpleSAMLphp SAML2 library has incorrect signature verification for HTTP-Redirect binding","details":"The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message. Versions 4.17.0 and 5.0.0-alpha.20 contain a fix for the issue.","published":"2025-03-11T19:04:52.135Z","modified":"2026-07-15T01:49:18.919051391Z","cvss":{"score":8.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"simplesamlphp/saml2","fixedVersion":"4.17.0"},{"ecosystem":"Packagist","name":"simplesamlphp/saml2","fixedVersion":"5.0.0-alpha.20"},{"ecosystem":"Packagist","name":"simplesamlphp/saml2-legacy","fixedVersion":"4.17.0"}],"fix":{"url":"https://github.com/simplesamlphp/saml2/commit/7867d6099dc7f31bed1ea10e5bea159c5623d2a0","label":"simplesamlphp/saml2@7867d60"},"references":[{"type":"WEB","url":"https://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113"},{"type":"WEB","url":"https://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00013.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27773.json"},{"type":"ADVISORY","url":"https://github.com/simplesamlphp/saml2/security/advisories/GHSA-46r4-f8gj-xg56"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-27773"},{"type":"FIX","url":"https://github.com/simplesamlphp/saml2/commit/7867d6099dc7f31bed1ea10e5bea159c5623d2a0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:18.919051391Z"}}