Incus, a system container and virtual machine manager, contains a flaw in its handling of pongo2 templates. The implementation of pongo2 allows arbitrary file reads and writes with root privileges, bypassing the intended chroot isolation. This leads to the possibility of reading any file on the host or overwriting files, including critical system binaries and configuration files, thereby compromising confidentiality, integrity, and availability of the entire system.

The vulnerability affects the Incus product under the lxc:incus vendor. All versions prior to 6.23.0 are impacted because the patch that disables unsafe template handling was introduced in that release.

The CVSS score of 10 indicates a severe threat. Although the EPSS score is not reported, the lack of a KEV listing does not reduce the risk because the flaw allows unrestricted root-level access to the file system. The attack vector is inferred to require authenticated access to the instance template functionality or a local foothold; an attacker can create or manipulate templates to gain direct root access to the host. This makes exploitation highly dangerous and likely if the vulnerability is present and the attacker has sufficient privileges or anonymity in the environment.