CVE-2026-63294Public exploitNetwork attack vector

Root code execution via symlink-following backup write

Published Aug 12, 2026 · Updated Aug 12, 2026

Link following in Canonical LXD allows remote authenticated users to execute arbitrary code as root on the Linux host via a crafted image. During image unpacking, internal/server/storage/utils.go rejects only a rootfs symlink, while UpdateInstanceBackupFile uses os.Create on backup.yaml without rejecting symlinks. An account with image and instance creation rights can overwrite /etc/ld.so.preload through the link, causing the next root process to load attacker-controlled code and compromise the host and other tenants.

CVSS severity9.9
Critical
EPSS probability1.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Link following in Canonical LXD allows remote authenticated users to execute arbitrary code as root on the Linux host via a crafted image. During image unpacking, internal/server/storage/utils.go rejects only a rootfs symlink, while UpdateInstanceBackupFile uses os.Create on backup.yaml without rejecting symlinks. An account with image and instance creation rights can overwrite /etc/ld.so.preload through the link, causing the next root process to load attacker-controlled code and compromise the host and other tenants.

The record

CVE
CVE-2026-63294
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
Canonical
Product
LXD
Classifications
CWE-59, CAPEC-132, CAPEC-233, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.0.0 <4.0.12
  2. Affected versionversion=5.0.0 <5.0.8
  3. Affected versionversion=5.21.0 <5.21.6
  4. Affected versionversion=6.0 <6.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Canonical · LXDversion=4.0.0 <4.0.12; version=5.0.0 <5.0.8; version=5.21.0 <5.21.6; version=6.0 <6.10

Published CVSS scores

9.9CanonicalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
CAPEC-132Symlink Attack
CAPEC-233Privilege Escalation
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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