{"id":"GHSA-95wr-3f2v-v2wh","summary":"Craft CMS has a host header injection leading to SSRF via resource-js endpoint","details":"### Summary\n\nThe `resource-js` endpoint in Craft CMS allows unauthenticated requests to proxy remote JavaScript resources. \nWhen `trustedHosts` is not explicitly restricted (default configuration), the application trusts the client-supplied Host header. \n\nThis allows an attacker to control the derived `baseUrl`, which is used in prefix validation inside `actionResourceJs()`. \nBy supplying a malicious Host header, the attacker can make the server issue arbitrary HTTP requests, leading to Server-Side Request Forgery (SSRF).\n\n### Details\n\nThe vulnerability exists in `AppController::actionResourceJs()`.\n\nThe function validates that the `url` parameter starts with `assetManager-\u003ebaseUrl`. However, `baseUrl` is derived from the current request host. If `trustedHosts` is not configured, the Host header is fully attacker-controlled.\n\nAttack chain:\n\n1. Attacker sends request with controlled `Host` header.\n2. Application derives `baseUrl` from the malicious Host.\n3. `url` parameter is required to start with this `baseUrl`.\n4. Validation passes.\n5. Guzzle performs a server-side HTTP request to the attacker-controlled host.\n6. SSRF occurs.\n\nThis does not rely on string parsing bypass. It relies on Host header trust.\n\n### PoC (safe reproduction steps)\n\nEnvironment:\n- Craft CMS 5.9.12\n- Default configuration (no trustedHosts restriction)\n- Docker deployment\n\n1. Start a listener inside the container:\n   python3 -m http.server 9999\n\n2. Send a request to resource-js with a controlled Host header.\n\n3. Observe that the internal listener receives a request (OOB confirmation).","aliases":["CVE-2026-41130"],"modified":"2026-05-05T16:11:51.690319Z","published":"2026-04-14T23:36:09Z","database_specific":{"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-04-14T23:36:09Z","nvd_published_at":"2026-04-22T00:16:28Z","cwe_ids":["CWE-918"]},"references":[{"type":"WEB","url":"https://github.com/craftcms/cms/security/advisories/GHSA-95wr-3f2v-v2wh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41130"},{"type":"WEB","url":"https://github.com/craftcms/cms/commit/ebe7e85f1c89700d64332f72492be2e9a594e783"},{"type":"PACKAGE","url":"https://github.com/craftcms/cms"}],"affected":[{"package":{"name":"craftcms/cms","ecosystem":"Packagist","purl":"pkg:composer/craftcms/cms"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0-RC1"},{"fixed":"5.9.15"}]}],"versions":["5.0.0","5.0.0-RC1","5.0.1","5.0.2","5.0.3","5.0.4","5.0.5","5.0.6","5.1.0","5.1.1","5.1.10","5.1.2","5.1.3","5.1.4","5.1.5","5.1.6","5.1.7","5.1.8","5.1.9","5.2.0","5.2.0-beta.1","5.2.0-beta.2","5.2.0-beta.3","5.2.0-beta.4","5.2.0-beta.5","5.2.0-beta.6","5.2.1","5.2.10","5.2.2","5.2.3","5.2.4","5.2.4.1","5.2.5","5.2.6","5.2.7","5.2.8","5.2.9","5.3.0","5.3.0-beta.1","5.3.0-beta.2","5.3.0.1","5.3.0.2","5.3.0.3","5.3.1","5.3.2","5.3.3","5.3.4","5.3.5","5.3.6","5.4.0","5.4.0.1","5.4.1","5.4.10","5.4.10.1","5.4.2","5.4.3","5.4.4","5.4.5","5.4.5.1","5.4.6","5.4.7","5.4.7.1","5.4.8","5.4.9","5.5.0","5.5.0.1","5.5.1","5.5.1.1","5.5.10","5.5.2","5.5.3","5.5.4","5.5.5","5.5.6","5.5.6.1","5.5.7","5.5.8","5.5.9","5.6.0","5.6.0.1","5.6.0.2","5.6.1","5.6.10","5.6.10.1","5.6.10.2","5.6.11","5.6.12","5.6.13","5.6.14","5.6.15","5.6.16","5.6.17","5.6.2","5.6.3","5.6.4","5.6.5","5.6.5.1","5.6.6","5.6.7","5.6.8","5.6.9","5.6.9.1","5.7.0","5.7.0-beta.1","5.7.0-beta.2","5.7.1","5.7.1.1","5.7.10","5.7.11","5.7.2","5.7.3","5.7.4","5.7.5","5.7.6","5.7.7","5.7.8","5.7.8.1","5.7.8.2","5.7.9","5.8.0","5.8.1","5.8.10","5.8.11","5.8.12","5.8.13","5.8.13.1","5.8.13.2","5.8.14","5.8.15","5.8.16","5.8.17","5.8.18","5.8.19","5.8.2","5.8.20","5.8.21","5.8.22","5.8.23","5.8.3","5.8.4","5.8.5","5.8.6","5.8.7","5.8.8","5.8.9","5.9.0","5.9.0-beta.1","5.9.0-beta.2","5.9.1","5.9.10","5.9.11","5.9.12","5.9.13","5.9.14","5.9.2","5.9.3","5.9.4","5.9.5","5.9.6","5.9.7","5.9.8","5.9.9"],"database_specific":{"last_known_affected_version_range":"\u003c= 5.9.14","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-95wr-3f2v-v2wh/GHSA-95wr-3f2v-v2wh.json"}},{"package":{"name":"craftcms/cms","ecosystem":"Packagist","purl":"pkg:composer/craftcms/cms"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0-RC1"},{"fixed":"4.17.9"}]}],"versions":["4.0.0","4.0.0-RC1","4.0.0-RC2","4.0.0-RC3","4.0.0.1","4.0.1","4.0.2","4.0.3","4.0.4","4.0.5","4.0.5.1","4.0.5.2","4.0.6","4.1.0","4.1.0.1","4.1.0.2","4.1.1","4.1.2","4.1.3","4.1.4","4.1.4.1","4.10.0","4.10.0-beta.1","4.10.0-beta.2","4.10.1","4.10.2","4.10.3","4.10.4","4.10.5","4.10.6","4.10.7","4.10.8","4.11.0","4.11.0.1","4.11.0.2","4.11.1","4.11.2","4.11.3","4.11.4","4.11.5","4.12.0","4.12.1","4.12.2","4.12.3","4.12.4","4.12.4.1","4.12.5","4.12.6","4.12.6.1","4.12.7","4.12.8","4.12.9","4.13.0","4.13.1","4.13.1.1","4.13.10","4.13.2","4.13.3","4.13.4","4.13.5","4.13.6","4.13.7","4.13.8","4.13.9","4.14.0","4.14.0.1","4.14.0.2","4.14.1","4.14.10","4.14.11","4.14.11.1","4.14.12","4.14.13","4.14.14","4.14.15","4.14.2","4.14.3","4.14.4","4.14.5","4.14.6","4.14.7","4.14.8","4.14.8.1","4.14.9","4.15.0","4.15.0-beta.1","4.15.0-beta.2","4.15.0.1","4.15.0.2","4.15.1","4.15.2","4.15.3","4.15.4","4.15.5","4.15.6","4.15.6.1","4.15.6.2","4.15.7","4.16.0","4.16.1","4.16.10","4.16.11","4.16.12","4.16.13","4.16.14","4.16.15","4.16.16","4.16.17","4.16.18","4.16.19","4.16.2","4.16.3","4.16.4","4.16.5","4.16.6","4.16.6.1","4.16.7","4.16.8","4.16.9","4.16.9.1","4.17.0","4.17.0-beta.1","4.17.0-beta.2","4.17.1","4.17.2","4.17.3","4.17.4","4.17.5","4.17.6","4.17.7","4.17.8","4.2.0","4.2.0.1","4.2.0.2","4.2.1","4.2.1.1","4.2.2","4.2.3","4.2.4","4.2.5","4.2.5.1","4.2.5.2","4.2.6","4.2.7","4.2.8","4.3.0","4.3.1","4.3.10","4.3.11","4.3.2","4.3.2.1","4.3.3","4.3.4","4.3.5","4.3.6","4.3.6.1","4.3.7","4.3.7.1","4.3.8","4.3.8.1","4.3.8.2","4.3.9","4.4.0","4.4.0-beta.1","4.4.0-beta.2","4.4.0-beta.3","4.4.0-beta.4","4.4.0-beta.5","4.4.0-beta.6","4.4.0-beta.7","4.4.1","4.4.10","4.4.10.1","4.4.11","4.4.12","4.4.13","4.4.14","4.4.15","4.4.16","4.4.16.1","4.4.17","4.4.2","4.4.3","4.4.4","4.4.5","4.4.6","4.4.6.1","4.4.7","4.4.7.1","4.4.8","4.4.9","4.5.0","4.5.0-beta.1","4.5.0-beta.2","4.5.1","4.5.10","4.5.11","4.5.11.1","4.5.12","4.5.13","4.5.14","4.5.15","4.5.2","4.5.3","4.5.4","4.5.5","4.5.6","4.5.6.1","4.5.7","4.5.8","4.5.9","4.6.0","4.6.0-RC1","4.6.1","4.7.0","4.7.1","4.7.2","4.7.2.1","4.7.3","4.7.4","4.8.0","4.8.1","4.8.10","4.8.11","4.8.2","4.8.3","4.8.4","4.8.5","4.8.6","4.8.7","4.8.8","4.8.9","4.9.0","4.9.1","4.9.2","4.9.3","4.9.4","4.9.5","4.9.6","4.9.7"],"database_specific":{"last_known_affected_version_range":"\u003c= 4.17.8","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-95wr-3f2v-v2wh/GHSA-95wr-3f2v-v2wh.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:P"}]}