{"id":"CVE-2026-68581","summary":"Vikunja 0.22.0 through 2.3.0 Authentication Bypass via Principal ID Collision","details":"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.","aliases":["GHSA-vvcv-vpph-h844"],"modified":"2026-08-04T11:31:17.600347373Z","published":"2026-08-02T12:15:27.893Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68581.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68581.json"},{"type":"ADVISORY","url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68581"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/vikunja-through-authentication-bypass-via-principal-id-collision"},{"type":"FIX","url":"https://github.com/go-vikunja/vikunja/commit/95b7e673fb5ee407498fa4b13e8b4c57847a4a0b"},{"type":"FIX","url":"https://github.com/go-vikunja/vikunja/commit/e6b25bd57b537ef9a72b5acdadf446ca5ef77bfa"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/go-vikunja/vikunja","events":[{"introduced":"f08fc8eeb4c82a85efbf480cebcd4146c6529e6a"},{"fixed":"907850feae3866ae9b16ea1c7b84a4d77273415a"}],"database_specific":{"extracted_events":[{"introduced":"0.22.0"},{"fixed":"2.4.0"}],"source":"AFFECTED_FIELD"}}],"versions":["v2.3.0","v2.2.2","v2.2.1","v2.2.0","v2.1.0","v2.0.0","v1.1.0","v1.0.0","v1.0.0-rc4","v1.0.0-rc3","v1.0.0-rc2","v1.0.0-rc1","v1.0.0-rc0","v0.24.1","v0.23.0","v0.22.1","v0.22.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68581.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V4","score":"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"}]}