CVE-2026-33743 Incus vulnerable to denial of source through crafted bucket backup file
An attacker with storage bucket access can crash the Incus daemon via a crafted backup file, causing control plane denial of service.
- 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-2026-33743?
CVE-2026-33743 is a medium-severity denial of service vulnerability in lxc incus, published on 26 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Incus is a system container and virtual machine manager. Prior to version 6.23.0, a specially crafted storage bucket backup can be used by an user with access to Incus' storage bucket feature to crash the Incus daemon. Repeated use of this attack can be used to keep the server offline causing a denial of service of the control plane API. This does not impact any running workload, existing containers and virtual machines will keep operating. Version 6.23.0 fixes the issue.
Weakness: CWE-770
Which versions are affected by CVE-2026-33743?
6 open source packages ship an affected version, including github.com/lxc/incus and github.com/lxc/incus/v6. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/lxc/incus Go | All versions | None |
github.com/lxc/incus Go | All versions to 0.7.0 | None |
github.com/lxc/incus Go | All versions to 0.7.0 | None |
github.com/lxc/incus/v6 Go | All versions | 6.23.0 |
github.com/lxc/incus/v6 Go | All versions | 6.23.0 |
github.com/lxc/incus/v6 Go | All versions | 6.23.0 |
Products include Linuxcontainers Incus.
How do I fix CVE-2026-33743?
Upgrade to a fixed version.
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-2026-33743 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33743 exists.
Other vulnerabilities in lxc incus
- CVE-2026-33897 Incus vulnerable to arbitrary file read and write through pongo templates
- CVE-2026-33945 Abitrary file write through systemd-creds option
- CVE-2026-33898 Local Incus UI web server vulnerable to nuthentication bypass
- CVE-2026-23953 Incus container environment configuration newline injection
- CVE-2026-23954 Incus container image templating arbitrary host file read and write
Sources
Also known as DEBIAN-CVE-2026-33743, GHSA-vg76-xmhg-j5x3, GO-2026-4886, UBUNTU-CVE-2026-33743.