CVE-2026-33945 Abitrary file write through systemd-creds option
Attackers can write arbitrary files as root via path traversal in systemd credential configuration, leading to privilege escalation or 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-2026-33945?
CVE-2026-33945 is a critical path traversal 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. Incus instances have an option to provide credentials to systemd in the guest. For containers, this is handled through a shared directory. Prior to version 6.23.0, an attacker can set a configuration key named something like `systemd.credential.../../../../../../root/.bashrc` to cause Incus to write outside of the `credentials` directory associated with the container. This makes use of the fact that the Incus syntax for such credentials is `systemd.credential.XYZ` where `XYZ` can itself contain more periods. While it's not possible to read any data this way, it's possible to write to arbitrary files as root, enabling both privilege escalation and denial of service attacks. Version 6.23.0 fixes the issue.
Weakness: CWE-22
Which versions are affected by CVE-2026-33945?
4 open source packages ship an affected version, including github.com/lxc/incus/v6 and github.com/lxc/incus. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
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 |
github.com/lxc/incus Go | All versions | None |
Products include Linuxcontainers Incus.
How do I fix CVE-2026-33945?
Upgrade github.com/lxc/incus/v6 to 6.23.0 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-33945 being exploited?
There is no known exploitation of CVE-2026-33945 in the wild and no public exploit code.
Other vulnerabilities in lxc incus
- CVE-2026-33897 Incus vulnerable to arbitrary file read and write through pongo templates
- 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
- CVE-2025-64507 Incus vulnerable to local privilege escalation through custom storage volumes
Sources
Also known as DEBIAN-CVE-2026-33945, GHSA-q4q8-7f2j-9h9f, GO-2026-4884, UBUNTU-CVE-2026-33945.