{"id":"CVE-2026-55824","aliases":["GHSA-3mr9-p497-58f6"],"url":"https://o3.security/vulnerability/CVE-2026-55824","summary":"Contao crawler leaks auth credentials to external hosts","details":"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.","published":"2026-07-31T19:04:00.322Z","modified":"2026-09-10T03:31:03.171511977Z","cvss":{"score":2.6,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N"},"epss":{"score":0.00154,"percentile":0.04951,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"contao/contao","fixedVersion":"5.3.47"},{"ecosystem":"Packagist","name":"contao/contao","fixedVersion":"5.7.7"},{"ecosystem":"Packagist","name":"contao/core-bundle","fixedVersion":"5.3.47"},{"ecosystem":"Packagist","name":"contao/core-bundle","fixedVersion":"5.7.7"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55824.json"},{"type":"ADVISORY","url":"https://github.com/contao/contao/security/advisories/GHSA-3mr9-p497-58f6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55824"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-10T03:31:03.171511977Z"}}