---
id: CVE-2026-68581
title: >-
  Vikunja versions 0.22.0 through 2.3.0 fail to validate the principal type in
  API token management
summary: >-
  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 lin…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-863
published: '2026-08-02'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:34:34.997'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68581'
references:
  - url: >-
      https://github.com/go-vikunja/vikunja/commit/95b7e673fb5ee407498fa4b13e8b4c57847a4a0b
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/go-vikunja/vikunja/commit/e6b25bd57b537ef9a72b5acdadf446ca5ef77bfa
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/vikunja-through-authentication-bypass-via-principal-id-collision
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00422
epssPercentile: 0.36198
ingestedAt: '2026-08-02T13:18:30.091Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.