LXD is widely used for container/VM hosting; vulnerability allows privileged host takeover across cloud and datacenter deployments, requiring org-wide action.
CVE-2026-87799
Authenticated LXD migration flaw allows arbitrary root file writes and full host takeover.
Is CVE-2026-87799 being exploited?
Not confirmed. CVE-2026-87799 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-87799?
CVE-2026-87799 is rated Critical with a CVSS score of 9.9. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-87799?
Yes. A fix has been recorded for CVE-2026-87799. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-87799 affect?
CVE-2026-87799 affects Canonical LXD (versions 4.0 and later prior to fixes), Linux hosts running LXD, LXD migration receive path (instances/custom storage volumes). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-87799?
Upgrade LXD to fixed versions immediately; restrict/disable untrusted migrations and project create permissions.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated instance/volume creators or malicious migration servers can use crafted rsync/btrfs streams to plant symlinks and write arbitrary files as root, enabling full host compromise.
Immediate action required
- affected>= 4.0.0 and < 4.0.14
- affected>= 5.0.0 and < 5.0.10
- affected>= 5.21.0 and < 5.21.8
- affected>= 6.0 and < 6.10
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.