Description
Contao is an open source content management system. Starting in version 4.9.0 and prior to versions 4.13.40 and 5.3.4, when checking for broken links on protected pages, Contao sends the cookie header to external urls as well, the passed options for the http client are used for all requests. Contao versions 4.13.40 and 5.3.4 have a patch for this issue. As a workaround, disable crawling protected pages.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| contao | contao | >= 4.9.0, < 4.13.40, >= 5.0.0-RC1, < 5.3.4 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Packagist | contao/core-bundle | >= 4.9.0, < 4.13.40 | 4.13.40 | GHSA-9jh5-qf84-x6pr |
| Packagist | contao/core-bundle | >= 5.0.0-RC1, < 5.3.4 | 5.3.4 | GHSA-9jh5-qf84-x6pr |
Advisories 1
- WID-SEC-2026-4445 Contao: Schwachstelle ermöglicht Offenlegung von Informationen BSI CERT-Bund (WID) · Nov 9, 2026
References
- https://github.com/contao/contao/security/advisories/GHSA-9jh5-qf84-x6pr
- https://github.com/contao/contao/commit/73a2770e2d3535ec9f1b03d54be00e56ebb8ff16
- https://github.com/contao/contao/commit/79b7620d01ce8f46ce2b331455e0d95e5208de3d
- https://contao.org/en/security-advisories/session-cookie-disclosure-in-the-crawler
- https://github.com/contao/contao/blob/14e9ef4bc8b82936ba2d0e04164581145a075e2a/core-bundle/src/Resources/contao/classes/Crawl.php#L129