Incus container image templating arbitrary host file read and write (lxc incus)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.78 % · percentile 56 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-22 — Improper Limitation of a Pathname to a Restricted Directory
References
- https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7
- https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215
- https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294
- https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh
- https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.7 | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N | GitHub_M |
| CVSS 3.1 | HIGH 8.7 | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-7f67-crqm-jgh7 — Incus container image templating arbitrary host file read and write
- GO-2026-4357 — Incus container image templating arbitrary host file read and write in github.com/lxc/incus
European references
- ENISA EUVD · EUVD-2026-3803
- GCVE · GCVE-0-2026-23954
Affected configurations (NVD CPE)
cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:*≤ 6.0.5cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:*≥ 6.1.0 < 6.21.0
Affected products
| Product | Versions |
|---|---|
| lxc · incus | affected >= 6.1.0, <= 6.20.0 ; affected <= 6.0.5 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |