How severe is CVE-2009-3640?

CVE-2009-3640 has a CVSS 2.0 base score of 4.9, rated medium severity.

Is CVE-2009-3640 being actively exploited?

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

What products are affected by CVE-2009-3640?

CVE-2009-3640 primarily affects Linux Linux Kernel. In total, 337 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-3640?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-3640 published?

CVE-2009-3640 was published on 2009-10-29 and last updated on 2026-06-16.

CVE-2009-3640

CVE-2009-3640 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 2.0 base score of 4.9. 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-20.

Key facts

Severity: Medium (CVSS 2.0 base score 4.9)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Linux Linux Kernel
Published: 2009-10-29
Last modified: 2026-06-16

Description

The update_cr8_intercept function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc1 does not properly handle the absence of an Advanced Programmable Interrupt Controller (APIC), which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly gain privileges via a call to the kvm_vcpu_ioctl function.

Frequently asked questions

What is CVE-2009-3640?: The update_cr8_intercept function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc1 does not properly handle the absence of an Advanced Programmable Interrupt Controller (APIC), which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly gain privileges via a call to the kvm_vcpu_ioctl function.
How severe is CVE-2009-3640?: CVE-2009-3640 has a CVSS 2.0 base score of 4.9, rated medium severity.
Is CVE-2009-3640 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3640?: CVE-2009-3640 primarily affects Linux Linux Kernel. In total, 337 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3640?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-3640 published?: CVE-2009-3640 was published on 2009-10-29 and last updated on 2026-06-16.

References

Affected products (337)

cpe:2.3:o:linux:linux_kernel:*:rc8:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.1:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.2:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.3:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.4:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.5:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.6:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.7:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.8:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.8.1:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.9:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.10:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.1:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.2:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.3:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.4:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.5:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.6:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.7:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.8:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.9:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.10:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.11:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.11.12:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12.1:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12.2:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12.3:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12.4:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12.5:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12.6:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.13:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.13.1:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.13.2:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.13.3:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.13.4:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.13.5:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.14:*:*:*:*:*:*:*

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