CVSS 9.9 (critical) · published 2026-08-24
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.
Affected products (NVD): canonical lxd
Fixed in (NVD): 4.0.13, 5.0.9, 5.21.7
Weakness: CWE-22, CWE-23
Source: NVD CVE-2026-66897
Connect an AI agent to the FixLane MCP server or ask the Telegram bot to check what you have installed against incidents with a verified fixed version.