{"id":"CVE-2026-55824","title":"Contao is an Open Source CMS","summary":"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 ext…","severity":"low","cvss":2.6,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N","cwe":["CWE-200"],"vendor":"contao","product":"contao/contao","affected":["contao/contao >= 4.13.0, < 5.3.47","contao/contao >= 5.4.0, < 5.7.7","contao/core-bundle >= 4.13.0, < 5.3.47","contao/core-bundle >= 5.4.0, < 5.7.7"],"patched":["contao/contao 5.3.47","contao/contao 5.7.7","contao/core-bundle 5.3.47","contao/core-bundle 5.7.7"],"published":"2026-07-31","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:51:43.490","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55824","references":[{"url":"https://github.com/contao/contao/security/advisories/GHSA-3mr9-p497-58f6","label":"security-advisories@github.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55824"},{"url":"https://github.com/contao/contao/commit/5bc6e3f900c439313df57aa561d0865792aafa05"},{"url":"https://github.com/contao/contao/commit/80425d28cdf66280a209bd3f5bc31b1a76901a04"},{"url":"https://contao.org/en/security-advisories/credentials-disclosure-in-the-crawler"},{"url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2026-55824.yaml"},{"url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2026-55824.yaml"},{"url":"https://github.com/advisories/GHSA-3mr9-p497-58f6"}],"tags":["nvd","ghsa","composer"],"epss":0.00154,"epssPercentile":0.04953,"aliases":["GHSA-3mr9-p497-58f6"],"ecosystem":"composer","ingestedAt":"2026-08-06T20:03:56.502Z","slug":"CVE-2026-55824","body":"## Overview\n\nContao 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55824)\n\nAffected packages:\n\n- `contao/contao >= 4.13.0, < 5.3.47`\n- `contao/contao >= 5.4.0, < 5.7.7`\n- `contao/core-bundle >= 4.13.0, < 5.3.47`\n- `contao/core-bundle >= 5.4.0, < 5.7.7`\n\nPatched in:\n\n- `contao/contao 5.3.47`\n- `contao/contao 5.7.7`\n- `contao/core-bundle 5.3.47`\n- `contao/core-bundle 5.7.7`\n\nSource: https://github.com/advisories/GHSA-3mr9-p497-58f6","depth":"sunlit","depthScore":14,"depthScoreParts":{"impact":14.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}