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TI-2026-58681 Aliases CVE-2026-85526

Path traversal via Btrfs optimized-backup subvolumes[].path enables root file/dir manipulation in LXD

Priority HIGH 76CWE-22Published · 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

Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00528 44th 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
Poc
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-2026-58518 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
    • TI-2026-59920 Arbitrary file write on LXD host via symlink in migration streamPriority MEDIUM 43
    Show all 4 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-85526

References

Patch 5

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