CVE-2026-68581
Vikunja 0.22.0 through 2.3.0 Authentication Bypass via Principal ID Collision
- State
- Published
- Severity
- 8.6 High
- Published
- Aug 2, 2026
- Updated
- Aug 3, 2026
- Reserved
- Jul 31, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.6 High | 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 | VulnCheck |
| 3.1 | 8.1 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-863 Incorrect Authorization
Affected Products
| Product | Versions |
|---|---|
vikunjago-vikunja |
|
References
- GitHub Security Advisory (GHSA-vvcv-vpph-h844)vendor-advisory
- Patch Commitpatch
- Patch Commitpatch
- VulnCheck Advisory: Vikunja 0.22.0 through 2.3.0 Authentication Bypass via Principal ID Collisionthird-party-advisory
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