CVE-2026-91979 Vikunja before 2.6.0 Denial of Service via Decompression Bomb
Authenticated users can crash the Vikunja instance by uploading decompression bombs during data import, exhausting server resources.
- 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-2026-91979?
CVE-2026-91979 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 before 2.6.0 fails to limit archive expansion during data import, allowing authenticated users to cause denial of service. Attackers can upload highly compressed files that expand to tens of gigabytes in memory and disk, exhausting server resources and crashing the instance.
Weakness: CWE-400
Which versions are affected by CVE-2026-91979?
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-2026-91979?
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-2026-91979 being exploited?
There is no known exploitation of CVE-2026-91979 in the wild and no public exploit code.
Sources
Also known as GHSA-w7jp-mf2v-8342, GO-2026-6756.