Symlink Following Affecting incus package, versions *


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.35% (27th percentile)

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  • Snyk IDSNYK-ECHOLATEST-INCUS-18496043
  • published1 Aug 2026
  • disclosed26 Mar 2026

Introduced: 26 Mar 2026

CVE-2026-33711  (opens in a new tab)
CWE-61  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest incus.

NVD Description

Note: Versions mentioned in the description apply only to the upstream incus package and not the incus package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

Incus is a system container and virtual machine manager. Incus provides an API to retrieve VM screenshots. That API relies on the use of a temporary file for QEMU to write the screenshot to which is then picked up and sent to the user prior to deletion. As versions prior to 6.23.0 use predictable paths under /tmp for this, an attacker with local access to the system can abuse this mechanism by creating their own symlinks ahead of time. On the vast majority of Linux systems, this will result in a "Permission denied" error when requesting a screenshot. That's because the Linux kernel has a security feature designed to block such attacks, protected_symlinks. On the rare systems with this purposefully disabled, it's then possible to trick Incus intro truncating and altering the mode and permissions of arbitrary files on the filesystem, leading to a potential denial of service or possible local privilege escalation. Version 6.23.0 fixes the issue.

CVSS Base Scores

version 3.1