{"id":"CVE-2026-91973","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-91973","summary":"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…","details":"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.","published":"2026-09-15T16:17:54.230","modified":"2026-09-15T16:17:54.230","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m469-88xx-8rx2"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-caldav-basicauth"},{"type":"WEB","url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m469-88xx-8rx2"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-09-15T16:17:54.230"}}