{"id":"CVE-2026-91973","revision":"edecf39170b24f549073a290a2c8ba6b","records":[{"revision":"edecf39170b24f549073a290a2c8ba6b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-91973","aliases":[],"title":"Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuth","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.","state":0,"publishedAt":"2026-09-15T15:18:23.488+00:00","modifiedAt":"2026-09-15T15:55:04.161+00:00","affected":[{"ecosystem":"Vendor product","name":"vikunja","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"go-vikunja\",\n                    \"product\": \"vikunja\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThan\": \"2.6.0\"\n                        },\n                        {\n                            \"version\": \"2.6.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","score":8.7,"severity":"HIGH"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5,"severity":"HIGH"}],"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"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-91973","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-91973","identifiers":["CVE-2026-91973"]},"retained":false,"historicalAffected":[]}],"coverage":[]}