CVE-2026-87799Network attack vectorHinoki check available

Host-root file write via migration-stream symlink

Published Sep 28, 2026 · Updated Sep 28, 2026

Improper link resolution in Canonical LXD 4.0 and later allows remote authenticated users to write arbitrary host files as root via migration. During instance or custom-volume reception, rsync or btrfs receive follows a symlink planted in the incoming stream, letting later entries escape the volume and overwrite host paths. A project user needs instance or custom-volume creation rights, or the target must migrate from a malicious source server; optimized ZFS transfers are unaffected.

CVSS severity9.9
Critical
EPSS probability0.41%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper link resolution in Canonical LXD 4.0 and later allows remote authenticated users to write arbitrary host files as root via migration. During instance or custom-volume reception, rsync or btrfs receive follows a symlink planted in the incoming stream, letting later entries escape the volume and overwrite host paths. A project user needs instance or custom-volume creation rights, or the target must migrate from a malicious source server; optimized ZFS transfers are unaffected.

The record

CVE
CVE-2026-87799
Published
Sep 28, 2026
Updated
Sep 28, 2026
Vendor
Canonical Ltd.
Product
LXD
Classifications
T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 28, 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 <4.0.14
  2. Affected versionversion=5.0.0 <5.0.10
  3. Affected versionversion=5.21.0 <5.21.8
  4. Affected versionversion=6.0 <6.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Canonical Ltd. · LXDversion=4.0.0 <4.0.14; version=5.0.0 <5.0.10; version=5.21.0 <5.21.8; 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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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