{"id":"CVE-2026-91981","revision":"0bc58b5a680a489ba2cf2cc6551fe4ad","records":[{"revision":"0bc58b5a680a489ba2cf2cc6551fe4ad","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-91981","aliases":[],"title":"Vikunja before 2.6.0 User Enumeration via v2 API","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":"2026-09-15T15:18:25.523+00:00","modifiedAt":"2026-09-21T18:47:28.55+00:00","affected":[{"ecosystem":"Vendor product","name":"vikunja","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"go-vikunja\",\n                    \"product\": \"vikunja\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:golang/code.vikunja.io/api\",\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 3.1","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"},{"system":"CVSS 4.0","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","score":5.3,"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://www.cve.org/CVERecord?id=CVE-2026-91981","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-91981","identifiers":["CVE-2026-91981"]},"retained":false,"historicalAffected":[]}],"coverage":[]}