CVE-2026-16033: Arbitrary file read+write on host via templates/ symlink in malicious image

Severity: high (CVSS 8.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-08-12 · updated 2026-10-23
Weakness: CWE-22

Description

A path traversal vulnerability in LXD allows an attacker to achieve arbitrary host file read or unconstrained file creation. When processing image metadata templates, LXD fails to properly sanitize or restrict template file paths from escaping the instance templates directory (specifically affecting virtual machine / QEMU driver execution paths). An attacker can exploit this flaw by providing a crafted image archive with malicious template directives containing path traversal sequences, causing LXD to access or write files outside the intended template directory on the host system.

Affected products

Canonical LXD: from 4.0.0 before 4.0.12; from 5.0.0 before 5.0.7 — fixed in 4.0.12, 5.0.7

How to fix

Upgrade to a fixed version: Canonical LXD 4.0.12, 5.0.7. Check the vendor advisory for mitigations.

References

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