Canonical Lxd
CVE-2026-63294
A link following vulnerability in LXD allows an attacker to achieve root command execution on the host system. During the import or unpacking of crafted image or backup archives, LXD fails to properly validate and confine the backup.yaml file when it exists as a symbolic link. An attacker can exploit this flaw by providing a malicious archive with a symlinked backup.yaml file, causing LXD to process unconfined configuration metadata and execute arbitrary commands with root privileges.
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 1% chance of attack attempts being seen in the next 30 days, ranking above 67% 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, follow the vendor's guidance. No patch reference has been published yet.
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.
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- Weakness
- CWE-59
- Assigned by
- security@ubuntu.com
Dates
- Published
- 2026-08-12
- Last modified
- 2026-09-11
- Sources
- NVD
Affected products
- Canonical Lxd4.0.0 - 4.0.12, 5.0.0 - 5.0.8, 5.1 - 5.21.6, 6.0 - 6.10
As listed in the NVD configuration data. Not a statement about your estate.