If the crawler is set to crawl protected pages, it sends the cookie header to externals URLs.
Update to Contao 4.13.40 or 5.3.4.
Disable crawling protected pages.
https://contao.org/en/security-advisories/session-cookie-disclosure-in-the-crawler
If you have any questions or comments about this advisory, open an issue in contao/contao.
{
"cwe_ids": [
"CWE-200"
],
"github_reviewed": true,
"github_reviewed_at": "2024-04-09T15:50:59Z",
"nvd_published_at": "2024-04-09T16:15:07Z",
"severity": "HIGH"
}