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Vulnerability · Published Aug 12, 2026 · Assigned by canonical

CVE-2026-66898Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE

Critical 9.9

In plain English

A critical-severity path traversal in LXD from Canonical. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).

Severity (CVSS 3.1)9.9Critical
Exploit odds (30 days)0.6%top 51.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12lxdno fix listedDEBIAN-CVE-2026-66898
Debian:13lxdno fix listedDEBIAN-CVE-2026-66898

Affected products (as reported)

VendorProductVersions
Canonical LXD 4.0.0 – before 4.0.125.0.0 – before 5.0.45.21.0 – before 5.21.26.0 – before 6.1

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References