Is CVE-2026-63125 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-63125 being exploited in the wild.

How severe is CVE-2026-63125?

Critical severity, with a CVSS score of 9.9, published 21 August 2026.

Which products and versions are affected?

Linux Containers Incus prior to 7.3.0.

Is there a fix for CVE-2026-63125?

A patch was published on 2026-07-30: Fixed in version 7.3.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-63125 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-63125?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-63125: Incus arbitrary file write via backup.yaml symlink

CVE-2026-63125 · Severity: critical · CVSS 9.9 · Published 2026-08-21

Incus is a container and virtual machine management system used by system administrators to provision and manage workloads. An unprivileged user with basic image and instance creation permissions can exploit a symlink vulnerability in backup file handling to write arbitrary files as root on the host system, leading to complete compromise of the Incus host and all tenants running on it.

Quick answers

Is CVE-2026-63125 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-63125 being exploited in the wild.
How severe is CVE-2026-63125?: Critical severity, with a CVSS score of 9.9, published 21 August 2026.
Which products and versions are affected?: Linux Containers Incus prior to 7.3.0.
Is there a fix for CVE-2026-63125?: A patch was published on 2026-07-30: Fixed in version 7.3.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-63125 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-63125?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a symlink-following bug (CWE-59/CWE-61) in Incus's backup file handling. When unpacking a crafted image, the daemon extracts a metadata tarball containing a symlinked backup.yaml into the instance directory. Later, UpdateInstanceBackupFile() creates the backup.yaml file without checking for symlinks (no O_NOFOLLOW flag) and follows the link to write instance configuration data as root. An unprivileged user with can_create_images and can_create_instances permissions can craft a malicious image where backup.yaml symlinks to /etc/ld.so.preload, then include an attacker-controlled shared library in the image and reference it via instance config. This causes arbitrary code execution as root when the next system process runs. The attack requires network access to the Incus API and valid project-confined credentials. Version 7.3.0 and later patch the issue by validating and rejecting symlinks during image unpacking.

Affected products

Linux Containers Incus prior to 7.3.0

Timeline

2026-07-30: disclosed: GitHub security advisory published
2026-08-21: advisory: NVD entry published
2026-07-30: patched: Fixed in version 7.3.0

References

https://github.com/lxc/incus/security/advisories/GHSA-6rqx-22hc-qm36

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