CVE-2026-68581
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://github.com/go-vikunja/vikunja/commit/95b7e673fb5ee407498fa4b13e8b4c57847a4a0b
- https://github.com/go-vikunja/vikunja/commit/e6b25bd57b537ef9a72b5acdadf446ca5ef77bfa
- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844
- https://www.vulncheck.com/advisories/vikunja-through-authentication-bypass-via-principal-id-collision
CWEs
CWE-863
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.