CVE-2026-54766 Vikunja: Project duplication bypasses write-permission check on the target parent project
Authenticated users can bypass write-permission checks to inject content into arbitrary project hierarchies during project duplication.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54766?
CVE-2026-54766 is a medium-severity missing authorization vulnerability in go-vikunja vikunja, published on 28 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Vikunja is an open-source self-hosted task management platform. From 0.21.0 until 2.4.0, the project duplication operation in pkg/models/project_duplicate.go allows an authenticated user who can read a source project to place its duplicate beneath an arbitrary target parent project. ProjectDuplicate.CanCreate calls parent.CanCreate on an unhydrated Project containing only the body supplied parent_project_id instead of calling parent.CanWrite, so the target parent write-permission check is skipped. The ordinary project creation path enforces that permission, but PUT /api/v1/projects/{project}/duplicate does not, allowing attacker-owned content to be injected into another user or team project hierarchy. This issue is fixed in version 2.4.0.
Which versions are affected by CVE-2026-54766?
3 open source packages ship an affected version, including code.vikunja.io/api.
| Package | Affected | Fixed in |
|---|---|---|
code.vikunja.io/api Go | From 0.21.0 | None |
code.vikunja.io/api Go | From 0.21.0 | 2.4.0 |
code.vikunja.io/api Go | From 0.21.0 | 2.4.0 |
How do I fix CVE-2026-54766?
Upgrade code.vikunja.io/api to 2.4.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-54766 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54766 exists.
Sources
Also known as GHSA-f27p-pw2p-9pr4, GO-2026-6311.