CVE-2026-87799

Arbitrary file write on LXD host via symlink in migration stream

Published Sep 28, 2026 CVSS 3.1 · 9.9 Critical EPSS < 1% KEV · Not listed
Description
Improper link resolution in the migration receive path in Canonical LXD versions 4.0 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client that can create instances or custom storage volumes in a project, or a malicious migration source server, to write attacker-controlled files to arbitrary paths on the target host as root, leading to full host compromise. The attacker does this with a crafted rsync or btrfs send stream that plants a symlink in the transferred volume, such as rootfs or root.img, and then writes through it.

Remediation

Vendor Solution

Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Canonical
Canonical lxd
Vendors & Products Canonical
Canonical lxd
Type Values Removed Values Added
Description Improper link resolution in the migration receive path in Canonical LXD versions 4.0 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client that can create instances or custom storage volumes in a project, or a malicious migration source server, to write attacker-controlled files to arbitrary paths on the target host as root, leading to full host compromise. The attacker does this with a crafted rsync or btrfs send stream that plants a symlink in the transferred volume, such as rootfs or root.img, and then writes through it.
Title Arbitrary file write on LXD host via symlink in migration stream
Weaknesses CWE-59
References
Metrics cvssV3_1

{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
canonical
Published
Updated
Sep 29, 2026, 3:55 AM
Reserved
Sep 9, 2026, 10:00 AM
Status
Deferred
Published
Sep 28, 2026, 2:17 PM
Modified
Sep 29, 2026, 4:18 AM