Use After Free Affecting qemu package, versions <1:2.11+dfsg-1ubuntu7.42+esm5


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.78% (52nd percentile)

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  • Snyk IDSNYK-UBUNTU1804-QEMU-13350802
  • published8 Oct 2025
  • disclosed3 Oct 2025

Introduced: 3 Oct 2025

CVE-2025-11234  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Ubuntu:18.04 qemu to version 1:2.11+dfsg-1ubuntu7.42+esm5 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream qemu package and not the qemu package as distributed by Ubuntu. See How to fix? for Ubuntu:18.04 relevant fixed versions and status.

A flaw was found in QEMU. If the QIOChannelWebsock object is freed while it is waiting to complete a handshake, a GSource is leaked. This can lead to the callback firing later on and triggering a use-after-free in the use of the channel. This can be abused by a malicious client with network access to the VNC WebSocket port to cause a denial of service during the WebSocket handshake prior to the VNC client authentication.

CVSS Base Scores

version 3.1