Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M
CVE-2026-41130Craft CMS has a host header injection leading to SSRF via resource-js endpoint
Medium 5.5
In plain English
A medium-severity server-side request forgery in cms from craftcms. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Craft CMS is a content management system (CMS). In versions on the 4.x branch through 4.17.8 and the 5.x branch through 5.9.14, the `resource-js` endpoint in Craft CMS allows unauthenticated requests to proxy remote JavaScript resources. When `trustedHosts` is not explicitly restricted (default configuration), the application trusts the client-supplied Host header. This allows an attacker to control the derived `baseUrl`, which is used in prefix validation inside `actionResourceJs()`. By supplying a malicious Host header, the attacker can make the server issue arbitrary HTTP requests, leading to Server-Side Request Forgery (SSRF). Versions 4.17.9 and 5.9.15 patch the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | craftcms/cms | 5.9.15 | GHSA-95wr-3f2v-v2wh |
| Packagist | craftcms/cms | 4.17.9 | GHSA-95wr-3f2v-v2wh |
Affected products (as reported)
Weakness: CWE-918 · Vector: 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