Vulnerability Report

CVE-2026-66897

Title: CVE-2026-66897

Arbitrary File Access

Proof Of Concept

No public PoC currently indexed for CVE-2026-66897.

CWE Category CWE-22

Published Date Aug 24, 2026

Modified Date Sep 11, 2026

Exploit Status Not Found

Score 9.9 CVSS v3.1

Exploit Probability (EPSS)

0.72%

Vulnerability Summary

CVE-2026-66897: 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.

Impacted Vendors

linuxcontainers 1

canonical 1

Reference Links

https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fv

CVSS v3.1

Source Entity [email protected]

Severity CRITICAL

9.9

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns