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NVD / CVE Program· CNA redhat

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

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.86% (FIRST EPSS); higher than 58.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: gitlab.com/qemu-project/qemu qemu 10.1.2; azl3 qemu 8.2.0-21 on Azure Linux 3.0 8.2.0-23; azl3 qemu 8.2.0-23 on Azure Linux 3.0 8.2.0-23.

Low priority for now. Upgrade to gitlab.com/qemu-project/qemu qemu 10.1.2; azl3 qemu 8.2.0-21 on Azure Linux 3.0 8.2.0-23; azl3 qemu 8.2.0-23 on Azure Linux 3.0 8.2.0-23 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Oct 3, 2025
Updated
Oct 18, 2026
EPSS
0.8% · 58th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-11234

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • gitlab.com/qemu-project/qemu qemu

    • 2.6.0 and later · before 10.1.2affected · semver

  • Red Hat Red Hat Enterprise Linux 10

    • 18:10.0.0-14.el10_1.5 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsunknown
    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 8

    • 8100020251120003312.489197e6 and laternot affected · rpm
    • 8100020251202222937.489197e6 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

    • 8040020260916092751.522a0ee4 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

    • 8040020260916092751.522a0ee4 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service

    • 8080020260910092120.63b34585 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

    • 8080020260910092120.63b34585 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 9

    • 17:10.1.0-17.el9_8 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

    • 17:6.2.0-11.el9_0.10 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

    • 17:7.2.0-14.el9_2.24 and laternot affected · rpm

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10qemu-guest-agentbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-imgbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvmbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-audio-pabefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-block-blkiobefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-block-curlbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-block-rbdbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-commonbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-corebefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-device-display-virtio-gpubefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-device-display-virtio-gpu-ccwbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-device-display-virtio-gpu-pcibefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-device-display-virtio-vgabefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-device-usb-hostbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-device-usb-redirectbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-docsbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-toolsbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-ui-egl-headlessbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-kvm-ui-openglbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:10qemu-pr-helperbefore 18:10.0.0-14.el10_1.5.alma.118:10.0.0-14.el10_1.5.alma.1
AlmaLinux:8hivexbefore 1.3.18-23.module_el8.6.0+2880+7d9e37031.3.18-23.module_el8.6.0+2880+7d9e3703
AlmaLinux:8hivexbefore 1.3.18-23.module_el8.6.0+3161+a07c0ea51.3.18-23.module_el8.6.0+3161+a07c0ea5
AlmaLinux:8hivex-develbefore 1.3.18-23.module_el8.6.0+2880+7d9e37031.3.18-23.module_el8.6.0+2880+7d9e3703
AlmaLinux:8hivex-develbefore 1.3.18-23.module_el8.6.0+3161+a07c0ea51.3.18-23.module_el8.6.0+3161+a07c0ea5

+96

Same product

red hat: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-10230Samba: command injection in wins server hook script
    52Plan
  • CVE-2026-4631Cockpit: cockpit: unauthenticated remote code execution due to ssh command-line argument injection
    44Plan
  • CVE-2026-76578Ipa: freeipa: freeipa: unauthenticated ldap client can obtain administrator credentials via the self-managed-token aci
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-11021Sep 26, 2025 · Libsoup: out-of-bounds read in cookie date handling of libsoup http library
    30Monitor
  • ← EarlierCVE-2025-7493Sep 30, 2025 · Freeipa: idm: privilege escalation from host to domain admin in freeipa
    36Monitor
  • Later →CVE-2025-11561Oct 9, 2025 · Sssd: sssd default kerberos configuration allows privilege escalation on ad-joined linux systems
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
gitlab.com/qemu-project/qemu qemu10.1.2Vendor (CNA)
azl3 qemu 8.2.0-21 on Azure Linux 3.08.2.0-23 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 qemu 8.2.0-23 on Azure Linux 3.08.2.0-23 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 qemu 6.2.0-24 on CBL Mariner 2.06.2.0-25 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 qemu 6.2.0-25 on CBL Mariner 2.06.2.0-25 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:qemu-guest-agent18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-img18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-audio-pa18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-block-blkio18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-block-curl18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-block-rbd18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-common18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-core18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu-ccw18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu-pci18:10.0.0-14.el10_1.5.alma.1 · AlmaLinux:10Package registry (OSV)
debian:qemu1:7.2+dfsg-7+deb12u18 · Debian:12Package registry (OSV)
opensuse:qemu8.2.10-150600.3.43.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:qemu-linux-user8.2.10-150600.3.43.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:qemu-guest-agent17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-guest-agent-debuginfo17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-img17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-img-debuginfo17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-kvm17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-kvm-audio-dbus-debuginfo17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-kvm-audio-pa17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-kvm-audio-pa-debuginfo17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-kvm-block-blkio17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)
red hat:qemu-kvm-block-blkio-debuginfo17:8.2.0-11.el9_4.18 · Red Hat:rhel_eus:9.4::appstreamPackage registry (OSV)

+17

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-93834357 days apartQemu-kvm: 9pfs: use-after-free race in tlcreate/twalk allows vm guest escape
    35Monitor
  • CVE-2026-96889355 days apartLibrsvg: use-after-free when xml includes have duplicated entities
    31Monitor
  • CVE-2026-108094374 days apartMutter: mutter: client-triggered use-after-free in wayland color-management icc image description path
    31Monitor
  • CVE-2026-112258381 days apartGimp: gimp: use-after-free in xcf loader via prop_linked and prop_selection on channels
    31Monitor
  • CVE-2026-112261381 days apartGimp: gimp: use-after-free in xcf loader via prop_selected_path
    31Monitor
  • CVE-2026-85197336 days apartLibsoup: libsoup: heap use-after-free in libsoup http/2 client on_data_read() via goaway during body upload
    30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (14 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records