Executive brief
Contao, an open-source content management system, contains a vulnerability in its Feed Reader module. This module is used to display external RSS feeds on a website. An authorized administrative user could exploit this flaw to force the server to make requests to internal network services or cloud metadata endpoints that are not intended to be public. This could lead to the exposure of sensitive internal information or infrastructure details.
Technical details
A Server-Side Request Forgery (SSRF) vulnerability exists in the Contao Feed Reader front-end module. The `FeedReaderController::getResponse()` function in `core-bundle/src/Controller/FrontendModule/FeedReaderController.php` iterates over configured RSS feed URLs and passes them to the `feedIo->read()` method without validating the URL scheme or checking for private IP addresses. Because the underlying Symfony HttpClient was not configured with SSRF protections (such as `NoPrivateNetworkHttpClient`), a backend user with permissions to edit modules can trigger requests to internal services, loopback addresses, or cloud metadata endpoints. The vulnerability is addressed in versions 5.3.48 and 5.7.9 by implementing a restricted HTTP client that blocks private network requests.
Affected products
- Contao Contao 5.3.35 through 5.3.47, 5.7.0-RC1 through 5.7.8
Timeline
- 2026-07-13: patched: Fixes committed to repository
- 2026-07-31: advisory: GitHub Advisory and NVD publication