CVE-2026-66897
CRITICALDescription
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.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
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CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 47% of all known CVEs.
References
Related Vulnerabilities
Other CWE-22 (Path Traversal) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-23897 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2023-32315 | High | 8.6 | 100% | KEV | Fix |
| CVE-2022-29464 | Critical | 9.8 | 100% | KEV + Ransom | - |
| CVE-2021-26086 | Medium | 5.3 | 100% | KEV | Fix |
| CVE-2021-22005 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2020-5902 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
Common questions
How do I fix CVE-2026-66897?
No published fix for CVE-2026-66897 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2026-66897 being actively exploited?
Not that we know of. CVE-2026-66897 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.62% is the estimated probability that it will be exploited in the next 30 days. That is higher than 47% of all scored CVEs.
How severe is CVE-2026-66897?
CVE-2026-66897 has a CVSS v3 base score of 9.9, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-28.