CVE-2026-86334: CLI Path Traversal via Content-Disposition in LXD Image Export/Copy

Severity: medium (CVSS 4.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-28 · updated 2026-09-28
Weakness: CWE-22

Description

Path traversal in the CLI client image export and copy functionality in Canonical LXD from 4.0.2 before 4.0.14, 5.0.10, 5.21.8, and 6.10 on all platforms allows a remote malicious or machine-in-the-middle image server to overwrite arbitrary local files and execute code on the client system via a crafted Content-Disposition header filename parameter during unified image export or copy operations into a local directory target.

Affected products

Canonical LXD: from 4.0.2 before 4.0.14; from 5.0.0 before 5.0.10; from 5.21.0 before 5.21.8; from 6.0 before 6.10 — fixed in 4.0.14, 5.0.10, 5.21.8, 6.10

How to fix

Upgrade to a fixed version: Canonical LXD 4.0.14, 5.0.10, 5.21.8, 6.10. Check the vendor advisory for mitigations.

References

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