Vulnerability Description
Contao is an Open Source CMS. In versions 4.13.40 through 5.3.46 and 5.7.0-RC1 through 5.7.6, the crawler leaks auth credentials to external hosts. Contao's crawler tries to prevent confidential HTTP client options from being sent to external domains by creating a scoped client: full options for root page origins, cleaned options for everything else. The cleaner removes Cookie and Authorization headers, but it removes the non-Symfony option names basic_auth and bearer_auth instead of Symfony HttpClient's real auth_basic and auth_bearer options. When contao.crawl.default_http_client_options contains Basic or Bearer authentication for a protected staging/production site, those credentials remain in the "clean" client used for external links or configured additional URIs. An attacker who can get an external URL crawled, for example through a link on a crawled page while the broken-link checker is enabled, can receive the crawler credentials. This issue has been fixed in versions 5.3.47 and 5.7.7.
CVSS Score
LOW
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-55824?
CVE-2026-55824 is a vulnerability with a CVSS score of 2.6 (LOW). Contao is an Open Source CMS. In versions 4.13.40 through 5.3.46 and 5.7.0-RC1 through 5.7.6, the crawler leaks auth credentials to external hosts. Contao's crawler tries to prevent confidential HTTP ...
How severe is CVE-2026-55824?
CVE-2026-55824 has been rated LOW with a CVSS base score of 2.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55824?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.