Link following in LXD - CVE-2026-48750
Published: June 29, 2026
Vulnerability identifier: #VU135800
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-48750
CWE-ID: CWE-59
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Containers
Affected software:
LXD
LXD
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary code on the host.
The vulnerability exists due to improper link resolution in the /instances/$name/exec endpoint exec-output handling when processing the record-output parameter for a crafted image. A remote user can create an instance from a crafted image and invoke exec with record-output enabled to execute arbitrary code on the host.
The issue arises because a top-level exec-output symlink from the image can be extracted as is, causing stdout and stderr files to be written to an arbitrary host location.
How to mitigate CVE-2026-48750
Install security update from vendor's website.