CVE-2026-66897Instance template path traversal allows arbitrary host file write as root
Updated under an hour ago ()
Does this affect you?
It affects Canonical LXD. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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
- 9.9 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-22, CWE-23
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- canonical
- NVD analysis
- Analyzed
- Record last updated
- Aug 25, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Canonical LXD canonical:lxd (from the name) | from 4.0.0 before 4.0.13; from 5.0.0 before 5.0.9; from 5.21.0 before 5.21.7; from 6.0 before 6.10 | CNA record |
canonical lxd canonical:lxd | before 4.0.13; from 5.0.0 before 5.0.9; from 5.1 before 5.21.7; from 6.0 through 6.9 | NVD |
References
- https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fvvdb-entry, vendor-advisory, exploit
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.