CVE-2026-23953

NameCVE-2026-23953
DescriptionIncus 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
incus (PTS)trixie6.0.4-2+deb13u3vulnerable
trixie (security)6.0.4-2+deb13u2vulnerable
forky, sid6.0.5-7vulnerable
lxd (PTS)bookworm, bookworm (security)5.0.2-5+deb12u2vulnerable
trixie5.0.2+git20231211.1364ae4-9+deb13u2vulnerable
trixie (security)5.0.2+git20231211.1364ae4-9+deb13u1vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
incussource(unstable)(unfixed)
lxdsource(unstable)(unfixed)

Notes

https://github.com/lxc/incus/security/advisories/GHSA-x6jc-phwx-hp32

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