{"id":"CVE-2026-91981","revision":"c6d4956f544646a39d0cc38c03b1d485","records":[{"revision":"c6d4956f544646a39d0cc38c03b1d485","observedAt":"2026-10-25T16:19:22.228+00:00","statement":{"source":"nvd","id":"CVE-2026-91981","aliases":[],"title":"Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist…","description":"Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint.","state":0,"publishedAt":"2026-09-15T16:17:55.087+00:00","modifiedAt":"2026-09-21T19:17:16.22+00:00","affected":[],"metrics":[{"system":"CVSS 4.0 · disclosure@vulncheck.com · Secondary","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","score":5.3,"severity":"MEDIUM"},{"system":"CVSS 3.1 · disclosure@vulncheck.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","score":4.3,"severity":"MEDIUM"}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vfxw-3x8p-2vjr","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-user-enumeration-via-v2-api"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91981","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Deferred","weaknesses":["CWE-200"],"productCriteria":[],"sourceDates":{"published":"2026-09-15T16:17:55.087","lastModified":"2026-09-21T19:17:16.220"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-91981","identifiers":["CVE-2026-91981"]},"retained":false,"historicalAffected":[]}],"coverage":[]}