How severe is CVE-2009-4004?

CVE-2009-4004 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2009-4004 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-4004?

CVE-2009-4004 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-4004?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2009-4004 published?

CVE-2009-4004 was published on 2009-11-20 and last updated on 2026-06-16.

CVE-2009-4004

CVE-2009-4004 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Linux Linux Kernel
Published: 2009-11-20
Last modified: 2026-06-16

Description

Buffer overflow in the kvm_vcpu_ioctl_x86_setup_mce function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc7 allows local users to cause a denial of service (memory corruption) or possibly gain privileges via a KVM_X86_SETUP_MCE IOCTL request that specifies a large number of Machine Check Exception (MCE) banks.

Frequently asked questions

What is CVE-2009-4004?: Buffer overflow in the kvm_vcpu_ioctl_x86_setup_mce function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc7 allows local users to cause a denial of service (memory corruption) or possibly gain privileges via a KVM_X86_SETUP_MCE IOCTL request that specifies a large number of Machine Check Exception (MCE) banks.
How severe is CVE-2009-4004?: CVE-2009-4004 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2009-4004 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-4004?: CVE-2009-4004 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-4004?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2009-4004 published?: CVE-2009-4004 was published on 2009-11-20 and last updated on 2026-06-16.

References

Affected products (8)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.32:rc6:*:*:*:*:*:*

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