CVE-2026-33945

Incus instances have an option to provide credentials to systemd in the guest. For containers, this is handled through a shared directory.
An attacker can use the name of a systemd credential to escape that directory and overwrite arbitrary files on the host system.

This can in turn be used to perform local privilege escalation or cause a DoS.

Details

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.

Credit

This issue was discovered and reported by the team at 7asecurity

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-33945 has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.23.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-33945? CVE-2026-33945 is a critical-severity path traversal vulnerability in github.com/lxc/incus/v6 (go), affecting versions < 6.23.0. It is fixed in 6.23.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-33945? CVE-2026-33945 has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/lxc/incus/v6 are affected by CVE-2026-33945? github.com/lxc/incus/v6 (go) versions < 6.23.0 is affected.
4. Is there a fix for CVE-2026-33945? Yes. CVE-2026-33945 is fixed in 6.23.0. Upgrade to this version or later.
5. Is CVE-2026-33945 exploitable, and should I be worried? Whether CVE-2026-33945 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-33945 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-33945? Upgrade github.com/lxc/incus/v6 to 6.23.0 or later.