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Fencer Intel
critical 9.9

CVE-2026-63294 json

Root RCE via image backup.yaml symlink

published 3mo ago modified 18d ago also EUVD-2026-57538 , GHSA-fv82-v4fj-mm4m

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository canonical/lxd. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
9.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

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.

Patch / fix

  • Canonical LXD 4.0.12, 5.0.8, 5.21.6, 6.10

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.88% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/canonical/lxd/security/advisories/GHSA-fv82-v4fj-mm4m referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Canonical LXD

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of canonical/lxd published their own advisory on GitHub. Reviewed sources take precedence over it.