lxc incus up to 6.0.5/6.20.0 Ttemplating path traversal

Summaryinfo

A vulnerability classified as critical was found in lxc incus up to 6.0.5/6.20.0. The affected element is an unknown function of the component Ttemplating. Such manipulation leads to path traversal. This vulnerability is traded as CVE-2026-23954. Access to the local network is required for this attack to succeed. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in lxc incus up to 6.0.5/6.20.0. Affected by this issue is an unknown function of the component Ttemplating. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the ‘incus’ group) to use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-23954 since 01/19/2026. The exploitation is known to be easy. The attack needs to approached within the local network. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1006.

The vulnerability scanner Nessus provides a plugin with the ID 296219 (Linux Distros Unpatched Vulnerability : CVE-2026-23954), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (296219) and EUVD (EUVD-2026-3803). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• lxc

Name

• incus

Version

• 6.0
• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9
• 6.10
• 6.11
• 6.12
• 6.13
• 6.14
• 6.15
• 6.16
• 6.17
• 6.18
• 6.19
• 6.20.0

Website

• Product: https://github.com/lxc/incus/

CPE 2.3info

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Once again VulDB remains the best source for vulnerability data.

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