{"id":"EUVD-2026-51991","revision":"8fa744ed79394960905d2e83706d780c","records":[{"revision":"8fa744ed79394960905d2e83706d780c","observedAt":"2026-10-30T10:59:53.127+00:00","statement":{"source":"euvd","id":"EUVD-2026-51991","aliases":["CVE-2026-68581","GHSA-9jrx-vmh8-c6xw","GHSA-vvcv-vpph-h844"],"title":"Vikunja versions 0.22.0 through 2.3.0 fail to validate the principal type in API token management. Because user IDs and link-share IDs are independent numeric sequences and both resolve through a generic web.Auth.GetID() interface, a link-s…","description":"Vikunja versions 0.22.0 through 2.3.0 fail to validate the principal type in API token management. Because user IDs and link-share IDs are independent numeric sequences and both resolve through a generic web.Auth.GetID() interface, a link-share JWT whose numeric ID equals a target user's ID is treated as that user by the /api/v1/tokens endpoints. An authenticated attacker can obtain a target's numeric user ID via authenticated user search, then create link shares on an attacker-writable project until the link-share sequence reaches that value, and use the resulting link-share JWT to list, create, and delete the target user's API tokens (including issuing a new token with attacker-chosen scopes under the target's permissions). Fixed in version 2.4.0.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","score":8.6,"severity":null}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844","https://github.com/go-vikunja/vikunja/commit/e6b25bd57b537ef9a72b5acdadf446ca5ef77bfa","https://github.com/go-vikunja/vikunja/commit/95b7e673fb5ee407498fa4b13e8b4c57847a4a0b","https://www.vulncheck.com/advisories/vikunja-through-authentication-bypass-via-principal-id-collision"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-51991","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Aug 2, 2026, 12:15:27 PM","dateUpdated":"Aug 3, 2026, 3:02:40 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-51991","identifiers":["EUVD-2026-51991","CVE-2026-68581","GHSA-9jrx-vmh8-c6xw","GHSA-vvcv-vpph-h844"]},"retained":false,"historicalAffected":[]}],"coverage":[]}