SECURELYN

CVE-2026-85185

Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs mi…

Scores

9.6
CVSS 9.6 out of 10, critical severity.
0.4%
EPSS 0.4% chance of exploitation in the next 30 days.

The facts

Published
28 September 2026
Last changed
28 September 2026
NVD status
Deferred
Severity
Critical, CVSS 9.6 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
0.4% chance of exploitation activity in the next 30 days (percentile 28).

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References