CVE-2026-28384

An improper sanitization of the compression_algorithm parameter in Canonical LXD allows an authenticated, unprivileged user to execute commands as the LXD daemon on the LXD server via API calls to the image and backup endpoints. This issue affected LXD from 4.12 through 6.6 and was fixed in the snap versions 5.0.6-e49d9f4 (channel 5.0/stable), 5.21.4-1374f39 (channel 5.21/stable), and 6.7-1f11451 (channel 6.0 stable). The channel 4.0/stable is not affected as it contains version 4.0.10.

What this means for your business

It affects Canonical Lxd. It matters if your company, or a supplier that handles your data, runs it.
Code showing how to exploit it has been published, but real attacks have not been confirmed.
An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
FIRST's prediction model gives it a 0.6% chance of attack attempts being seen in the next 30 days, ranking above 47% of all known flaws.

What to do

1Check whether your company or your suppliers run Canonical Lxd, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS: 9.9 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4: 9.4
Weakness: CWE-78
Assigned by: security@ubuntu.com

Dates

Published: 2026-03-12
Last modified: 2026-09-18
Sources: NVD

Affected products

Canonical Lxd4.12 - 5.0.6, 5.21.0 - 5.21.4, 6.0 - 6.7

As listed in the NVD configuration data. Not a statement about your estate.