Vulnerability Description
A path traversal vulnerability in LXD's instance template processing allows an attacker with container edit permissions, or any user launching a crafted image, to overwrite arbitrary files on the host system as root. When processing target template paths specified in metadata.yaml, LXD validates the path against a confined os.Root directory handle but subsequently opens and creates the file using os.Create with an unconfined string path. This discrepancy between path resolution checks and file creation allows an attacker to escape directory confinement, overwrite root-owned host files, and achieve host root code execution.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Canonical | Lxd | < 4.0.13 |
Related Weaknesses (CWE)
References
- https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fvVendor AdvisoryExploit
FAQ
What is CVE-2026-66897?
CVE-2026-66897 is a vulnerability with a CVSS score of 9.9 (CRITICAL). A path traversal vulnerability in LXD's instance template processing allows an attacker with container edit permissions, or any user launching a crafted image, to overwrite arbitrary files on the host...
How severe is CVE-2026-66897?
CVE-2026-66897 has been rated CRITICAL with a CVSS base score of 9.9/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-66897?
Check the references section above for vendor advisories and patch information. Affected products include: Canonical Lxd.