Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/go-vikunja/vikunja/commit/95b7e673fb5ee407498fa4b13e8b4c57847
- https://github.com/go-vikunja/vikunja/commit/e6b25bd57b537ef9a72b5acdadf446ca5ef
- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844
- https://www.vulncheck.com/advisories/vikunja-through-authentication-bypass-via-p
- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844
FAQ
What is CVE-2026-68581?
CVE-2026-68581 is a vulnerability with a CVSS score of 8.1 (HIGH). 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 gene...
How severe is CVE-2026-68581?
CVE-2026-68581 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-68581?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.