CVE-2016-9777

KVM in the Linux kernel before 4.8.12, when I/O APIC is enabled, does not properly restrict the VCPU index, which allows guest OS users to gain host OS privileges or cause a denial of service (out-of-bounds array access and host OS crash) via a crafted interrupt request, related to arch/x86/kvm/ioapic.c and arch/x86/kvm/ioapic.h.

Published: 2016-12-28 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-9777 is rated Low Risk (35.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2016-9777

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 2026-05-17 0.07% 0.04% -0.03%
2 2025-03-30 0.35% 0.07% -0.28%
3 2025-03-29 — 0.35% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9777

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.1 6.0 [email protected]
6.9 2.0 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.4 10.0 [email protected]

Weakness enumeration for CVE-2016-9777

OS Trackers for CVE-2016-9777

vendor priority summary link
debian not yet assigned CVE-2016-9777 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-9777
redhat high — https://access.redhat.com/security/cve/CVE-2016-9777
ubuntu medium CVE-2016-9777 medium priority: Ubuntu including 27 source packages (linux, linux-armadaxp, …), 162 status rows across 6 suites (precise, trusty, upstream, xenial, yakkety, zesty): DNE 104, released 31, not-affected 20, ignored 7. https://ubuntu.com/security/CVE-2016-9777

Affected software / configurations for CVE-2016-9777

Vendor Product Version Raw CPE
linux linux_kernel >= 4.8, < 4.8.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2016-9777

cvelogic Threat Intelligence