Vulnerability · Published Jan 22, 2026 · Assigned by GitHub_M
CVE-2026-23954Incus container image templating arbitrary host file read and write
High 8.7
In plain English
A high-severity path traversal in incus from lxc. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | incus | 6.0.5-r6 | ALPINE-CVE-2026-23954 |
| Alpine:v3.24 | incus | 6.0.5-r6 | ALPINE-CVE-2026-23954 |
| Alpine:v3.23 | incus-feature | 6.21.0-r0 | ALPINE-CVE-2026-23954 |
| Alpine:v3.24 | incus-feature | 6.21.0-r0 | ALPINE-CVE-2026-23954 |
| Debian:13 | incus | 6.0.4-2+deb13u4 | DEBIAN-CVE-2026-23954 |
| Debian:13 | incus | 6.0.4-2+deb13u4 | DSA-6109-1 |
| Debian:14 | incus | 6.0.5-8 | DEBIAN-CVE-2026-23954 |
| Debian:12 | lxd | no fix listed | DEBIAN-CVE-2026-23954 |
| Debian:12 | lxd | 5.0.2-5+deb12u3 | DSA-6153-1 |
| Debian:13 | lxd | 5.0.2+git20231211.1364ae4-9+deb13u3 | DSA-6153-1 |
| Debian:13 | lxd | 5.0.2+git20231211.1364ae4-9+deb13u3 | DEBIAN-CVE-2026-23954 |
| Go | github.com/lxc/incus | no fix listed | GO-2026-4357 |
| Go | github.com/lxc/incus/v6 | no fix listed | GO-2026-4357 |
| Go | github.com/lxc/incus/v6/cmd/incusd | no fix listed | GHSA-7f67-crqm-jgh7 |
| Ubuntu:25.10 | incus | no fix listed | UBUNTU-CVE-2026-23954 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
References
- https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7 x_refsource_CONFIRM
- https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215 x_refsource_MISC
- https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294 x_refsource_MISC
- https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh x_refsource_MISC
- https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch x_refsource_MISC