CVE-2026-68581: go-vikunja vikunja Incorrect Authorization

Vulnerability summary

CVE-2026-68581 is a high (CVSS 8.6) Incorrect Authorization vulnerability in go-vikunja vikunja. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 39.1% of scored vulnerabilities.

Timeline

1. 02-08-2026
   PublishedVulnerability first disclosed.
2. 03-08-2026
   Last modifiedVulnerability information updated.

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.

• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.