CVE-2026-33897: critical vulnerability in lxc incus
Incus vulnerable to arbitrary file read and write through pongo templates
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 10epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
lxc · incusRelated CVEs — lxc incus
In the same product, most dangerous first.
CVE-2026-48769CRITICALIncus has an arbitrary file write on its client due to trusted image hashEPSS 0.8%CVE-2026-48755CRITICALIncus has an argument injection in backup compression algorithm leading to AFW and ACEEPSS 0.8%CVE-2026-48752CRITICALIncus has arbitrary file read+write on host via templates/ symlink in malicious imageEPSS 0.8%CVE-2026-48750CRITICALIncus has an arbitrary file write on host via `exec-output` symlink in crafted imageEPSS 0.8%CVE-2026-48749CRITICALIncus has an arbitrary file read+write on host via rootfs/ symlink in malicious imageEPSS 0.8%CVE-2026-23954HIGHIncus container image templating arbitrary host file read and writeEPSS 0.8%