Vulnerability in Linuxcontainers Incus
CVE-2026-33711
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (7.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.002 · change: -0.002
Affected products
- Linuxcontainers Incus
- Lxc Incus — versions < 6.23.0
Weakness classification (CWE)
References
- github.com/lxc/incus/security/advisories/GHSA-q9vp-3wcg-8p4x (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-33711?
- CVE-2026-33711 is a high-severity vulnerability in Linuxcontainers Incus, classified under UNIX Symbolic Link (Symlink) Following. CVSS score: 7.8/10. Published 2026-03-26.
- How severe is CVE-2026-33711?
- High severity. CVSS v3 base score is 7.8 out of 10.