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

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.

Published: 2025-10-03 Last update: 2026-06-01 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-11234 is rated Moderate Risk (42.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.14%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-11234

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-01 0.16% 0.14% -0.01%
2 2026-05-23 0.13% 0.16% +0.03%
3 2026-05-22 — 0.13% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-11234

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-11234

GitHub Security Advisory for CVE-2025-11234

GHSA-hm8v-8c3v-cxfq · Severity: high — A flaw was found in QEMU. If the QIOChannelWebsock object is freed while it is waiting to...

OS Trackers for CVE-2025-11234

vendor priority summary link
debian not yet assigned CVE-2025-11234 not yet assigned priority: Debian including 1 source packages (qemu), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2025-11234
redhat medium — https://access.redhat.com/security/cve/CVE-2025-11234
suse high — https://www.suse.com/security/cve/CVE-2025-11234/
ubuntu medium CVE-2025-11234 medium priority: Ubuntu including 1 source packages (qemu), 9 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): needed 4, released 3, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2025-11234

Affected software / configurations for CVE-2025-11234

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-11234

cvelogic Threat Intelligence