---
id: CVE-2026-77159
title: >-
  A symlink-following flaw was found in libvirt's qemuTPMEmulatorPrepareHost()
  function
summary: >-
  A symlink-following flaw was found in libvirt's qemuTPMEmulatorPrepareHost()
  function. The function uses a path-based chown() on the swtpm logfile without
  checking for symbolic links. A local attacker with access to the swtpm account
  can…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-61
vendor: Red Hat
product: libvirt
affected:
  - libvirt (all versions)
  - libvirt
  - libvirt
  - 'virt:rhel/libvirt (all versions)'
  - libvirt (all versions)
published: '2026-09-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T19:42:43.623'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77159'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-77159'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2531811'
    label: secalert@redhat.com
  - url: 'https://gitlab.com/libvirt/libvirt/-/work_items/909'
    label: secalert@redhat.com
  - url: 'https://gitlab.com/libvirt/libvirt/-/work_items/909'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00162
epssPercentile: 0.05853
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T15:39:11.306501Z'
ingestedAt: '2026-09-12T18:47:14.696Z'
---

## Overview

A symlink-following flaw was found in libvirt's qemuTPMEmulatorPrepareHost() function. The function uses a path-based chown() on the swtpm logfile without checking for symbolic links. A local attacker with access to the swtpm account can replace the logfile with a symlink, causing libvirtd (running as root) to transfer ownership of an arbitrary file to the swtpm user.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.