CVE-2026-33897
Incus vulnerable to arbitrary file read and write through pongo templates in github.com/lxc/incus
Description
Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root on the host server. Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem. This was allowed such that a template could theoretically read a file and then generate a new version of said file. Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem with root privileges. Version 6.23.0 patches the issue.
How to fix CVE-2026-33897
To remediate CVE-2026-33897, upgrade the affected package to a fixed version below.
- —upgrade to 6.0.4-2+deb13u5 or later
- —upgrade to 5.0.2-5+deb12u4 or later
- —no fix listed
- —no fix listed
- —upgrade to 6.23.0 or later
- —upgrade to 6.23.0 or later
Is CVE-2026-33897 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (6)
- from 0, < 6.0.4-2+deb13u5
- from 0, < 5.0.2-5+deb12u4
- from 0, <= 0.7.0
- from 0
- from 0, < 6.23.0
- from 0, < 6.23.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |