CVE-2025-11234

Qemu-kvm: vnc websocket handshake use-after-free

At a glance

Severity: HIGH 7.5
EPSS: EPSS 0.86 % · percentile 58 (2026-10-27)
State: PUBLISHED
Published: 2025-10-03
Updated: 2026-10-09
Assigner: redhat
NVD status: Deferred

Description

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.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	redhat
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD · secalert@redhat.com (Secondary)

Weaknesses (CWE)

CWE-416

European references

ENISA EUVD · EUVD-2025-32560
GCVE · GCVE-0-2025-11234

CERT-FR advisories

CERTFR-2026-AVI-0326 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
CERTFR-2026-AVI-0316 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
CERTFR-2025-AVI-0899 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr

Affected products

Product	Versions
qemu	affected 2.6.0 < 10.1.2
Red Hat · Red Hat Enterprise Linux 10	unaffected 18:10.0.0-14.el10_1.5 < *
Red Hat · Red Hat Enterprise Linux 8	unaffected 8100020251120003312.489197e6 < *
Red Hat · Red Hat Enterprise Linux 8	unaffected 8100020251202222937.489197e6 < *
Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support	unaffected 8040020260916092751.522a0ee4 < *
Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On	unaffected 8040020260916092751.522a0ee4 < *
Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service	unaffected 8080020260910092120.63b34585 < *
Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions	unaffected 8080020260910092120.63b34585 < *
Red Hat · Red Hat Enterprise Linux 9	unaffected 17:10.1.0-17.el9_8 < *
Red Hat · Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions	unaffected 17:6.2.0-11.el9_0.10 < *
Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions	unaffected 17:7.2.0-14.el9_2.24 < *
Red Hat · Red Hat Enterprise Linux 9.4 Extended Update Support	unaffected 17:8.2.0-11.el9_4.18 < *
Red Hat · Red Hat Enterprise Linux 9.4 Extended Update Support	unaffected 17:8.2.0-11.el9_4.19 < *
Red Hat · Red Hat OpenShift Container Platform 4.12	unaffected 412.86.202608241157-0 < *
Red Hat · Red Hat OpenShift Container Platform 4.16	unaffected 416.94.202601071926-0 < *
Red Hat · Red Hat OpenShift Container Platform 4.17	unaffected 417.94.202601120213-0 < *
Red Hat · Red Hat OpenShift Container Platform 4.18	unaffected 418.94.202601071817-0 < *
Red Hat · Red Hat Enterprise Linux 6
Red Hat · Red Hat Enterprise Linux 7
Red Hat · Red Hat Enterprise Linux 7

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD