{"id":"CVE-2026-45074","aliases":["GHSA-j8gj-9rm5-4xhx"],"url":"https://o3.security/vulnerability/CVE-2026-45074","summary":"Symfony: Cas2Handler Derives CAS service URL from Client Host Header → Cross-Service Ticket Replay","details":"`Cas2Handler` builds this `service` parameter from `Request::getSchemeAndHttpHost()`, which reflects the attacker-controlled HTTP `Host` header whenever Symfony's `framework.trusted_hosts` setting is not configured (the default). An attacker who controls any *other* application registered with the same CAS server can replay a victim's ticket against the Symfony application, with a spoofed `Host` header, and be authenticated as that victim.\n\n### Resolution\n\nA new required `service_url` configuration option is introduced on `Cas2Handler`. The CAS `service` parameter sent to the validation endpoint is now built from this configured URL instead of being derived from the request's `Host` header, preventing cross-service ticket replay via Host header spoofing.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/5ba145dba702404801bdf9e7e8d6df170060d541) for branch 7.4.\n\n### Credits\n\nSymfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and Nicolas Grekas for providing the fix.","published":"2026-07-14T17:49:24.895Z","modified":"2026-08-12T03:51:16.740644872Z","cvss":null,"epss":{"score":0.00488,"percentile":0.4094,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"symfony/security-http","fixedVersion":"7.4.12"},{"ecosystem":"Packagist","name":"symfony/security-http","fixedVersion":"8.0.12"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"7.4.12"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"8.0.12"}],"fix":{"url":"https://github.com/symfony/symfony/commit/5ba145dba702404801bdf9e7e8d6df170060d541","label":"symfony/symfony@5ba145d"},"references":[{"type":"WEB","url":"https://github.com/symfony/symfony/releases/tag/v7.4.12"},{"type":"WEB","url":"https://github.com/symfony/symfony/releases/tag/v8.0.12"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45074.json"},{"type":"ADVISORY","url":"https://github.com/symfony/symfony/security/advisories/GHSA-j8gj-9rm5-4xhx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45074"},{"type":"FIX","url":"https://github.com/symfony/symfony/commit/5ba145dba702404801bdf9e7e8d6df170060d541"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2026-45074.yaml"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45074.yaml"},{"type":"PACKAGE","url":"https://github.com/symfony/symfony"},{"type":"WEB","url":"https://symfony.com/cve-2026-45074"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:16.740644872Z"}}