# Vikunja authorization bypass in link share deletion

Source: https://junglewise.ai/threats/vikunja-write-level-project-members-can-delete-admin-tier-link-shares-0fd718f8  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-09. Updated: 2026-10-09  
License: CC BY 4.0 with a link back

Severity: medium · Published 2026-10-09

Vikunja is a task and project management platform. A project member with basic write permissions can delete sensitive admin-level access links that should only be removable by administrators, potentially revoking legitimate user access and causing service disruption for external collaborators.

Technologies: [code.vikunja.io/api (Go)](https://junglewise.ai/threats/technologies/code-vikunja-io-api), [Vikunja](https://junglewise.ai/threats/technologies/vikunja). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Vikunja](https://junglewise.ai/threats/vendors/vikunja).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, published 9 October 2026.

**Which products and versions are affected?** code.vikunja.io/api (Go) >= 0.13.0, <= 2.6.0; Vikunja >= 0.13.0, <= 2.6.0.

**Is there a fix for This vulnerability?** No fixed version is recorded yet. Restrict link share deletion permissions at the database or access control layer to project administrators only until an update is available. Audit project membership and revoke write-level access for untrusted collaborators. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is This vulnerability attacked?** It is attacked over the network, in a web application.

**Am I affected?** Check whether you run code.vikunja.io/api (Go) or Vikunja at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix


Restrict link share deletion permissions at the database or access control layer to project administrators only until an update is available. Audit project membership and revoke write-level access for untrusted collaborators.

## Technical details

An authorization bypass in the link share deletion handler fails to load the stored share object before checking permissions, instead checking against a zero-initialized permission field. Since the zero value is Read (0) rather than the stored Admin (2), the check incorrectly falls through to Write-level authorization. This affects both v1 and v2 API endpoints for deletion; creation properly rejects Write members attempting to create admin shares.

## Affected products

- Vikunja Vikunja >= 0.13.0, <= 2.6.0

## Timeline

- 2026-10-09: disclosed

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