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TI-2026-59920 Aliases CVE-2026-87799

Arbitrary file write on LXD host via symlink in migration stream

Priority MEDIUM 43CWE-59Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00407 35th percentileScored 2026-11-07
Fix Fixed LXD (Canonical): 4.0.14, 5.0.10, 5.21.8 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CanonicalLXD4.0.0 to before 4.0.14; 5.0.0 to before 5.0.10; 5.21.0 to before 5.21.8; 6.0 to before 6.104.0.14, 5.0.10, 5.21.8, 6.10Patch availableCNA
  • LXD VendorCanonical Affected 4.0.0 to before 4.0.14; 5.0.0 to before 5.0.10; 5.21.0 to before 5.21.8; 6.0 to before 6.10 Fixed in 4.0.14, 5.0.10, 5.21.8, 6.10 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*——Canonical
  • cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:* Versions — — ·Canonical

Remediation

  • Fix · CNA LXD (Canonical) Fixed in 4.0.14, 5.0.10, 5.21.8, 6.10

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Canonical LXD 4.0.14, 5.0.10 and 2 more versions

    4 records Highest priority Priority HIGH 2 HIGH, 2 MEDIUM

    Other records, highest priority first

    • TI-2026-58681 Path traversal via Btrfs optimized-backup subvolumes[].path enables root file/dir manipulation in LXDPriority HIGH 76
    • TI-2026-58518 Path traversal in LXD btrfs storage driver allows arbitrary file deletion and write on host as rootPriority HIGH 74
    • TI-2026-59106 CLI Path Traversal via Content-Disposition in LXD Image Export/CopyPriority MEDIUM 53
    Show all 4 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-87799

References

Advisory 1

  • TI-2020-09349 An issue was discovered in SaltStack Salt before 2019.2.4 and 3000 before 3000.2. KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-05854 smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other… KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-01431 Netlogon Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-12627 Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than… KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-07471 OS command injection in exim KEVCVSS 3.1CRITICAL 9.8
See all 4301 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences