Is CVE-2016-9603 being actively exploited?

CVE-2016-9603 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2016-9603?

CVE-2016-9603 has a CVSS 3.0 base score of 5.5 (MEDIUM).

CVE-2016-9603

MEDIUM · CVSS 5.5EPSS 4.4%EU EUVD

A heap buffer overflow flaw was found in QEMU's Cirrus CLGD 54xx VGA emulator's VNC display driver support before 2.9; the issue could occur when a VNC client attempted to update its display after a VGA operation is performed by a guest. A privileged user/process inside a guest could use this flaw to crash the QEMU process or, potentially, execute arbitrary code on the host with privileges of the QEMU process.

Key facts

CVSS score: 5.5 (v3.0)
Severity: MEDIUM
CVSS vector: CVSS:3.0/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
Weakness (CWE): CWE-122
EPSS score: 4.4% (91th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2016-10407)
Published: July 27, 2018
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2016-10407 in the EU Vulnerability Database. Last updated in EUVD on August 6, 2024.

View on the EU Vulnerability Database

Affected products

citrix / xenserver
citrix / xenserver
citrix / xenserver
citrix / xenserver
citrix / xenserver
debian / debian linux
qemu / qemu
redhat / enterprise linux desktop
redhat / enterprise linux desktop
redhat / enterprise linux server
redhat / enterprise linux server
redhat / enterprise linux server aus
redhat / enterprise linux server aus
redhat / enterprise linux server eus
redhat / enterprise linux server eus
redhat / enterprise linux server eus
redhat / enterprise linux workstation
redhat / enterprise linux workstation
redhat / openstack
redhat / openstack
redhat / openstack
redhat / openstack
redhat / openstack
redhat / openstack

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

Citrix XenServer ® 7.1 LTSR Enterprise Edition (CU2) - Citrix Systems, Inc. - Common Criteria 383-4-467 - archived

References

http://www.securityfocus.com/bid/96893(Third Party Advisory, VDB Entry)
http://www.securitytracker.com/id/1038023(Third Party Advisory, VDB Entry)
https://access.redhat.com/errata/RHSA-2017:0980(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0981(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0982(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0983(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0984(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0985(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0987(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:0988(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:1205(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:1206(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2017:1441(Third Party Advisory)
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-9603(Issue Tracking, Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2018/02/msg00005.html(Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2018/09/msg00007.html
https://security.gentoo.org/glsa/201706-03(Third Party Advisory)
https://support.citrix.com/article/CTX221578(Third Party Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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