What’s Vulnerable › Vulnerabilities
CVE-2026-87799: Arbitrary file write on LXD host via symlink in migration stream
- Severity: critical (CVSS 9.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-28 · updated 2026-09-29
- Weakness: CWE-59
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.
Affected products
- Canonical LXD: from 4.0.0 before 4.0.14; from 5.0.0 before 5.0.10; from 5.21.0 before 5.21.8; from 6.0 before 6.10 — fixed in 4.0.14, 5.0.10, 5.21.8, 6.10
How to fix
Upgrade to a fixed version: Canonical LXD 4.0.14, 5.0.10, 5.21.8, 6.10. Check the vendor advisory for mitigations.
References
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