CVE-2026-87799: critical vulnerability in Canonical LXD
Arbitrary file write on LXD host via symlink in migration stream
Published · Updated
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.9epss 0.4%
exploitation probability
0.4%top 67% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
Canonical · LXDRelated CVEs — Canonical LXD
In the same product, most dangerous first.
CVE-2026-63294CRITICALRoot RCE via image backup.yaml symlinkEPSS 0.9%CVE-2026-66897CRITICALInstance template path traversal allows arbitrary host file write as rootEPSS 0.7%CVE-2026-63298HIGHLXD arbitrary lxc.conf directive injection via NVIDIA instance configurationEPSS 0.7%CVE-2026-9640HIGHLXD Snapshot Import Privilege Escalation VulnerabilityEPSS 0.6%CVE-2026-66898CRITICALPath traversal via unvalidated instance name in backup tarball restore enables root file write / RCEEPSS 0.6%CVE-2026-63293CRITICALArbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as rootEPSS 0.6%