CVE-2026-91973 [HIGH] – Vikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth e

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.