{"id":"CVE-2026-85526","published":"2026-09-28T14:17:20.423","lastModified":"2026-09-29T04:18:00.690","description":"Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import.","cvssScore":9.9,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cwes":["CWE-22"],"vendors":[],"products":[],"references":[{"url":"https://github.com/canonical/lxd-private/pull/103","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/104","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/105","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/84","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/87","tags":[]},{"url":"https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv","tags":[]}],"exploitRefs":[{"url":"https://github.com/canonical/lxd-private/pull/103","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/104","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/105","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/84","tags":[]},{"url":"https://github.com/canonical/lxd-private/pull/87","tags":[]},{"url":"https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv","tags":[]}],"hasPoc":true,"ai":{"summary":"This flaw allows an authenticated user to traverse paths and delete or replace arbitrary files and directories on the host filesystem, posing a significant risk due to the elevated privileges involved.","exploitability":"Exploitation requires an authenticated user with instance creation privileges, making it moderately hard to exploit.","blast_radius":"If exploited, this flaw could lead to complete host compromise, as the attacker can perform operations as root.","remediation":"Disable btrfs optimized backup import functionality or restrict access to the affected feature.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","auth-bypass","filesystem","privilege-escalation"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-29T08:50:02.785Z"}}