CVE-2026-12411: Broken Access Control in Canonical LXD DevLXD API

Severity: critical (CVSS 9.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-26 · updated 2026-10-25
Weakness: CWE-639

Description

Broken Access Control in the devLXDInstancePatchHandler component of Canonical LXD allows an untrusted guest to mount, read, and overwrite another guest's custom storage volume via a crafted device PATCH request over /dev/lxd when security.devlxd.management.volumes is enabled.

Affected products

Canonical LXD: from 6.6 before 6.9 — fixed in 6.9

How to fix

Upgrade to a fixed version: Canonical LXD 6.9. Check the vendor advisory for mitigations.

References

https://github.com/canonical/lxd/pull/18585
https://github.com/canonical/lxd/security/advisories/GHSA-hhf9-qw4v-72xp
https://github.com/canonical/lxd/security/advisories/GHSA-hhf9-qw4v-72xp

Get alerted when CVE-2026-12411 or the next vulnerability affects your stack