CVE-2026-23953

CVE-2026-23953 · Incus container environment configuration newline injection

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Incus is a system container and virtual machine manager. In versions 6.20.0 and below, a user with the ability to launch a container with a custom YAML configuration (e.g a member of the ‘incus’ group) can create an environment variable containing newlines, which can be used to add additional configuration items in the container’s lxc.conf due to newline injection. This can allow adding arbitrary lifecycle hooks, ultimately resulting in arbitrary command execution on the host. Exploiting this issue on IncusOS requires a slight modification of the payload to change to a different writable directory for the validation step (e.g /tmp). This can be confirmed with a second container with /tmp mounted from the host (A privileged action for validation only). A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.

CVSS 8.7 · High · EPSS 0.5% · Fix available

Published

2026-01-22T21:39:41.015Z

Updated

2026-01-26T21:00:46.311Z

Stack: system

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