---
id: GHSA-9jrx-vmh8-c6xw
title: >-
  Duplicate Advisory: Vikunja: Link-share principal ID collision allows
  cross-account API token issuance and management
summary: >-
  Duplicate Advisory: Vikunja: Link-share principal ID collision allows
  cross-account API token issuance and management
severity: high
cvss: 8.1
cwe:
  - CWE-863
vendor: api
product: code.vikunja.io/api
ecosystem: go
affected:
  - 'code.vikunja.io/api >= 0.22.0, <= 2.3.0'
published: '2026-08-02'
updated: '2026-10-09'
sourceUpdated: '2026-10-09T20:42:08Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-9jrx-vmh8-c6xw'
references:
  - url: >-
      https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vvcv-vpph-h844
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68581'
  - url: >-
      https://github.com/go-vikunja/vikunja/commit/95b7e673fb5ee407498fa4b13e8b4c57847a4a0b
  - url: >-
      https://github.com/go-vikunja/vikunja/commit/e6b25bd57b537ef9a72b5acdadf446ca5ef77bfa
  - url: >-
      https://www.vulncheck.com/advisories/vikunja-through-authentication-bypass-via-principal-id-collision
  - url: 'https://github.com/advisories/GHSA-9jrx-vmh8-c6xw'
tags:
  - ghsa
  - go
ingestedAt: '2026-10-09T21:12:42.335Z'
---

## Overview

### Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-vvcv-vpph-h844. This link is maintained to preserve external references.

### Original 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.

## Affected packages

- `code.vikunja.io/api >= 0.22.0, <= 2.3.0`

## Remediation

Refer to the advisory for the patched release.