CVE-2026-87799

Critical

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.

SeverityCritical
CVSS9.9
Exploit probability—
ProductLXD
PublishedSep 28, 2026
First seenSep 28, 2026

How to fix

Update
  • Canonical LXD4.0.14, 5.0.10, 5.21.8, 6.10 or later

Affected products

ProductAffected versionsFixed in
Canonical LXD4.0.0 ≤ v < 4.0.14, 5.0.0 ≤ v < 5.0.10, 5.21.0 ≤ v < 5.21.8, 6.0 ≤ v < 6.104.0.14, 5.0.10, 5.21.8, 6.10

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CVE-2026-87799 · LXD · Dark Radar