Arbitrary file write on LXD host via symlink in migration stream

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.

Scores

EPSS (exploitation in 30 days)

0.41% · top 65% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.9.

Weakness

• CWE-59 Improper link resolution before file access ('link following') (opens in a new tab)All about CWE-59 and its CVEs

Affected products

• Canonical · LXD

  • affected 4.0.0 – < 4.0.14
  • affected 5.0.0 – < 5.0.10
  • affected 5.21.0 – < 5.21.8
  • affected 6.0 – < 6.10

What to do

Solution: Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later.

References (1)

• https://github.com/canonical/lxd/security/advisories/GHSA-fmc3-3cpq-6whr (opens in a new tab)vendor-advisory

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-87799](https://trackcve.app/badge/CVE-2026-87799.svg)](https://trackcve.app/cve/CVE-2026-87799)

Record last updated 29 Sept 2026, 03:55 UTC.