Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2016-4020

23
FAUCET Score

CVE-2016-4020 describes an information disclosure vulnerability in QEMU's KVM virtual APIC implementation, specifically within the patch_instruction function in hw/i386/kvmvapic.c, affecting products like Canonical, Debian, QEMU, and Red Hat. This medium-severity vulnerability (CVSS 6.5) allows a local guest OS administrator to access sensitive host stack memory by manipulating the Task Priority Register (TPR), leading to high confidentiality impact. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
<= 2.6.2CPE matchmatch criteria
cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*
12.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
14.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
15.10CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
16.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.5MEDIUM

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

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
2.0
Impact Score
4.0
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.37%
Probability of exploitation in next 30 days
EPSS Percentile
29.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0037 is in the 86th percentile among its peer group of 15,938 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (9)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: qemu-kvm-10:1.5.3-141.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux OpenStack Platform 6.0 (Juno) for RHEL 7Fixed in: qemu-kvm-rhev-10:2.9.0-10.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux OpenStack Platform 7.0 (Kilo) for RHEL 7Fixed in: qemu-kvm-rhev-10:2.9.0-10.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenStack Platform 10.0 (Newton)Fixed in: qemu-kvm-rhev-10:2.9.0-10.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenStack Platform 11.0 (Ocata)Fixed in: qemu-kvm-rhev-10:2.9.0-10.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenStack Platform 8.0 (Liberty)Fixed in: qemu-kvm-rhev-10:2.9.0-10.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenStack Platform 9.0 (Mitaka)Fixed in: qemu-kvm-rhev-10:2.9.0-10.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Virtualization 4 for Red Hat Enterprise Linux 7Fixed in: qemu-kvm-rhev-10:2.9.0-14.el7
View patch
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux OpenStack Platform 5 (Icehouse)Fixed in: qemu-kvm-rhev

Vendor Advisories (1)

redhatCVE-2016-4020Low

Qemu: i386: leakage of stack memory to guest in kvmvapic.c

Apr 7, 2016

References

git.qemu.org
access.redhat.com / errata/RHSA-2017:1856
Third Party Advisory
access.redhat.com / errata/RHSA-2017:2392
Third Party Advisory
access.redhat.com / errata/RHSA-2017:2408
Third Party Advisory
bugzilla.redhat.com / show_bug.cgi
Issue TrackingThird Party Advisory
lists.debian.org / debian-lts-announce/2018/11/msg00038.html
Mailing ListThird Party Advisory
lists.gnu.org / archive/html/qemu-devel/2016-04/msg01106.html
PatchThird Party Advisory
lists.gnu.org / archive/html/qemu-devel/2016-04/msg01118.html
PatchThird Party Advisory
security.gentoo.org / glsa/201609-01
Third Party Advisory
securityfocus.com / bid/86067
Third Party AdvisoryVDB Entry
ubuntu.com / usn/USN-2974-1
Third Party Advisory