CVE-2026-87799: Canonical Lxd

Critical severity, CVSS 9.9. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Canonical Lxd: from 4.0.0, before 4.0.14 (fixed in 4.0.14); from 5.0.0, before 5.0.10 (fixed in 5.0.10); from 5.21.0, before 5.21.8 (fixed in 5.21.8); from 6.0, before 6.10 (fixed in 6.10)

Published 2026-09-28. Last modified 2026-09-29.