CVE-2025-11234: Qemu-kvm: vnc websocket handshake use-after-free

Published Oct 3, 2025
·
Updated

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.

Affected Software

4 affected components
Qemu Qemu
Microsoft azl3 qemu 8.2.0-19
Microsoft cbl2 qemu 6.2.0-24
Microsoft azl3 qemu 8.2.0-21

Event History

Oct 3, 2025
Data Sourced
via Red Hat·09:48 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·10:30 AM
Data Sourced
via MITRE·10:30 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·11:15 AM
DescriptionSeverityWeakness
Oct 7, 2025
Data Sourced
via Microsoft·01:01 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·01:01 AM
Affected Software
Updated
via Microsoft·01:01 AM
DescriptionSeverity
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Frequently Asked Questions

1

What is the severity of CVE-2025-11234?

CVE-2025-11234 has a moderate severity level due to the potential for a use-after-free vulnerability in QEMU.

2

How do I fix CVE-2025-11234?

To fix CVE-2025-11234, update your QEMU installation to the latest version that includes the patch addressing this vulnerability.

3

Who is affected by CVE-2025-11234?

Users of QEMU versions prior to the patch release that addresses CVE-2025-11234 are vulnerable.

4

What is the nature of the vulnerability in CVE-2025-11234?

CVE-2025-11234 involves a flaw where the QIOChannelWebsock object can lead to a use-after-free condition if freed prematurely.

5

Can CVE-2025-11234 be exploited remotely?

Yes, a malicious client could exploit CVE-2025-11234 to trigger the use-after-free condition, potentially compromising the system.

Contact

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