CVE-2026-91984 Vikunja before 2.6.0 Broken Object-Level Authorization via task-position
Authenticated attackers can modify task positions in other users' projects by bypassing object-level authorization checks.
- 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-2026-91984?
CVE-2026-91984 is a medium-severity missing authorization vulnerability in go-vikunja vikunja, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Vikunja before 2.6.0 fails to validate that user-supplied project_view_id in task-position requests belongs to the task's project. Authenticated attackers can insert task position rows into arbitrary other tenant project views via POST or PUT task-position endpoints.
Weakness: CWE-639
Which versions are affected by CVE-2026-91984?
3 open source packages ship an affected version, including code.vikunja.io/api.
| Package | Affected | Fixed in |
|---|---|---|
code.vikunja.io/api Go | All versions | None |
code.vikunja.io/api Go | All versions | 2.6.0 |
code.vikunja.io/api Go | All versions | 2.6.0 |
How do I fix CVE-2026-91984?
Upgrade code.vikunja.io/api to 2.6.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-91984 being exploited?
There is no known exploitation of CVE-2026-91984 in the wild and no public exploit code.
Sources
Also known as GHSA-w39f-h553-h2mx, GO-2026-6755.