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TI-2026-45140 Aliases CVE-2026-63294

Root RCE via image backup.yaml symlink

Priority HIGH 76CWE-59Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00878 59th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed LXD (Canonical): 4.0.12, 5.0.8, 5.21.6 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CanonicalLXD4.0.0 to before 4.0.12; 5.0.0 to before 5.0.8; 5.21.0 to before 5.21.6; 6.0 to before 6.104.0.12, 5.0.8, 5.21.6, 6.10Patch availableCNA
  • LXD VendorCanonical Affected 4.0.0 to before 4.0.12; 5.0.0 to before 5.0.8; 5.21.0 to before 5.21.6; 6.0 to before 6.10 Fixed in 4.0.12, 5.0.8, 5.21.6, 6.10 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*4.0.0 to before 4.0.12; 5.0.0 to before 5.0.8; 5.1 to before 5.21.6; 6.0 to before 6.10VulnerableCanonical
  • cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:* Versions 4.0.0 to before 4.0.12; 5.0.0 to before 5.0.8; 5.1 to before 5.21.6; 6.0 to before 6.10 Vulnerable ·Canonical

Remediation

  • Fix · CNA LXD (Canonical) Fixed in 4.0.12, 5.0.8, 5.21.6, 6.10

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Canonical LXD 4.0.12, 5.0.8 and 2 more versions

    3 records Highest priority Priority HIGH 2 HIGH, 1 MEDIUM

    Other records, highest priority first

    • TI-2026-45139 Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as rootPriority HIGH 76
    • TI-2026-45141 Project restriction `restricted.containers.privilege=isolated` bypassable by omitting `security.idmap.isolated`Priority MEDIUM 53
    Show all 3 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63294

References

Exploit 1

  • TI-2026-22659 Authenticated RCE via unsanitized compression_algorithm CVSS 4.0CRITICAL 9.4
  • TI-2026-47475 Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE CVSS 3.1CRITICAL 9.9
  • TI-2026-45146 Cross-project instance move bypasses all project restrictions allowing host command execution CVSS 3.1CRITICAL 9.9
  • TI-2026-45143 Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge CVSS 3.1CRITICAL 9.9
  • TI-2026-45142 Project restriction bypass via instance migration config override CVSS 3.1CRITICAL 9.9
  • TI-2026-45139 Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root CVSS 3.1CRITICAL 9.9
See all 34 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences