CVE-2026-57232: Contao: Server-Side Request Forgery (SSRF) via Unvalidated RSS Feed URL in Feed Reader Module

Severity: low (CVSS 3.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-31 · updated 2026-09-08
Weakness: CWE-918

Description

Contao is an Open Source CMS. From 5.3.35 through 5.3.47 and from 5.7.0-RC1 through 5.7.8, the Feed Reader front-end module passes configured RSS feed URLs from FeedReaderController::getResponse() to feedIo->read() without scheme or private-address validation, allowing a backend user with module-edit permissions to make the server request internal network services, loopback addresses, or cloud metadata endpoints. In core-bundle/src/Controller/FrontendModule/FeedReaderController.php, the getResponse() function iterates over the configured feed URLs and passes each one directly to the HTTP client (via $this->feedIo->read($url, new Feed())) with no validation, while the DCA field definition for rss_feed in tl_module.php carries no URL scheme or host validation and the HTTP client is wired as @psr18.http_client (Symfony HttpClient) with no SSRF protection configured, since NoPrivateNetworkHttpClient is not used. This issue is fixed in versions 5.3.48.

Affected products

contao: from 5.7.0-RC1, < 5.7.9; from 5.3.35, < 5.3.48

References

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