This advisory has been withdrawn because it is a duplicate of GHSA-m469-88xx-8rx2. This link is maintained to preserve external references.
Vikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth endpoints that lack rate limiting protection. Remote unauthenticated attackers can issue unbounded credential-guessing requests against /dav, /.well-known, and /feeds routes to bypass the instance's anti-brute-force controls and compromise password-only accounts.
{
"cwe_ids": [
"CWE-307"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-09T20:51:57Z",
"nvd_published_at": "2026-09-15T16:17:54Z",
"severity": "HIGH"
}