Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root (lxc incus)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.48 % · percentile 41 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Deferred
Description
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a `metadata.yaml` symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The `exec-output` and `templates/` paths were patched in a prior release using `Lstat` rejection and `os.OpenRoot` confinement; `metadata.yaml` was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
Weaknesses (CWE)
- CWE-73 — External Control of File Name or Path
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | CRITICAL 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | GitHub_M |
| CVSS 3.1 | CRITICAL 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | NVD · security-advisories@github.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-63989
- GCVE · GCVE-0-2026-63343
Affected products
| Product | Versions |
|---|---|
| lxc · incus | affected < 7.3.0 |
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 |