CVE-2026-91968 vikunja before 2.6.0 Denial of Service via unbounded filter recursion
Authenticated attackers can cause denial of service in Vikunja by submitting deeply nested filter expressions that exhaust server memory.
- 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-2026-91968?
CVE-2026-91968 is a high-severity denial of service 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 versions before 2.6.0 contain a resource exhaustion vulnerability in the task-filter endpoint that accepts deeply nested filter expressions without recursion depth limits. Authenticated attackers can supply thousands of nested parentheses in the filter query parameter to exhaust memory and terminate the API process.
Weakness: CWE-674
Which versions are affected by CVE-2026-91968?
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 | From 2.5.0 | 2.6.0 |
code.vikunja.io/api Go | From 2.5.0 | 2.6.0 |
How do I fix CVE-2026-91968?
Upgrade code.vikunja.io/api to 2.6.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-91968 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91968 exists.
Sources
Also known as GHSA-xxc3-xpmc-vmvr, GO-2026-6759.