CVE-2026-91973

Description

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.

CVSS Vector

References

• https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m469-88xx-8rx2
• https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-caldav-basicauth
• https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m469-88xx-8rx2