# CVE-2026-86334: Canonical LXD path traversal in image export and copy

Source: https://junglewise.ai/threats/cve-2026-86334-path-traversal-in-the-cli-client-image-export-and-copy  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-28. Updated: 2026-09-28  
License: CC BY 4.0 with a link back

CVE-2026-86334 · Severity: medium · CVSS 4.2 · Published 2026-09-28

Canonical LXD, a container and virtual machine manager, is vulnerable to path traversal in its image export and copy functionality. A malicious image server or network attacker can craft a specially designed response to overwrite arbitrary files on the client system and execute code, compromising the system hosting the LXD client.

Technologies: [Canonical LXD](https://junglewise.ai/threats/technologies/lxd). Vendors: [Canonical](https://junglewise.ai/threats/vendors/canonical).

## Quick answers

**Is CVE-2026-86334 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86334 being exploited in the wild.

**How severe is CVE-2026-86334?** Medium severity, with a CVSS score of 4.2, published 28 September 2026.

**Which products and versions are affected?** Canonical LXD 4.0.2 to before 4.0.14, 5.0.10, 5.21.8, and 6.10.

**Is there a fix for CVE-2026-86334?** A patch was published on 2026-09-02: Fix merged in PR #18940 to main branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-86334 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-86334?** Check whether you run Canonical LXD at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in LXD's CLI image export and copy operations, where the Content-Disposition header filename parameter from server responses is not properly sanitized. An attacker controlling a malicious image server or performing a machine-in-the-middle attack can supply crafted filenames containing path traversal sequences (e.g., "../") to write files outside the intended directory during unified image operations targeting a local directory. The attack requires the client to initiate an image operation against the attacker's server.

## Affected products

- Canonical LXD 4.0.2 to before 4.0.14, 5.0.10, 5.21.8, and 6.10

## Timeline

- 2026-09-28: disclosed: CVE-2026-86334 published
- 2026-09-02: patched: Fix merged in PR #18940 to main branch
- 2026-09-11: patched: Fix backported to stable-5.21 branch in PR #18974

## References

- [https://github.com/canonical/lxd/pull/18940](https://github.com/canonical/lxd/pull/18940)
- [https://github.com/canonical/lxd/pull/18974](https://github.com/canonical/lxd/pull/18974)

## Related threats

- [LXD project restriction bypass in instance copy](https://junglewise.ai/threats/lxd-has-project-restriction-bypass-in-instance-copy-across-projects-48d466e0)
- [Canonical LXD improper certificate validation in HTTPS listener](https://junglewise.ai/threats/cve-2026-112816-improper-certificate-validation-in-the-https-listener-in)
- [Canonical LXD custom storage volume authorization bypass](https://junglewise.ai/threats/cve-2026-97335-incorrect-authorization-in-the-custom-storage-volume-creation)
- [Canonical LXD arbitrary file write via symlink in migration stream](https://junglewise.ai/threats/cve-2026-87799-improper-link-resolution-in-the-migration-receive-path-in)
- [Canonical LXD improper symlink resolution in recursive file pull](https://junglewise.ai/threats/cve-2026-87798-improper-link-resolution-in-the-recursive-file-pull-feature-of)