How severe is CVE-2009-1242?

CVE-2009-1242 has a CVSS 2.0 base score of 4.9, rated medium severity.

Is CVE-2009-1242 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-1242?

CVE-2009-1242 primarily affects Linux Linux Kernel. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-1242?

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

When was CVE-2009-1242 published?

CVE-2009-1242 was published on 2009-04-06 and last updated on 2026-06-16.

CVE-2009-1242

CVE-2009-1242 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% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Linux Linux Kernel
Published: 2009-04-06
Last modified: 2026-06-16

Description

The vmx_set_msr function in arch/x86/kvm/vmx.c in the VMX implementation in the KVM subsystem in the Linux kernel before 2.6.29.1 on the i386 platform allows guest OS users to cause a denial of service (OOPS) by setting the EFER_LME (aka "Long mode enable") bit in the Extended Feature Enable Register (EFER) model-specific register, which is specific to the x86_64 platform.

Frequently asked questions

What is CVE-2009-1242?: The vmx_set_msr function in arch/x86/kvm/vmx.c in the VMX implementation in the KVM subsystem in the Linux kernel before 2.6.29.1 on the i386 platform allows guest OS users to cause a denial of service (OOPS) by setting the EFER_LME (aka "Long mode enable") bit in the Extended Feature Enable Register (EFER) model-specific register, which is specific to the x86_64 platform.
How severe is CVE-2009-1242?: CVE-2009-1242 has a CVSS 2.0 base score of 4.9, rated medium severity.
Is CVE-2009-1242 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-1242?: CVE-2009-1242 primarily affects Linux Linux Kernel. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-1242?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-1242 published?: CVE-2009-1242 was published on 2009-04-06 and last updated on 2026-06-16.

References

Affected products (10)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:11.0:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:11.1:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:4.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:5.0:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:8.04:*:*:*:-:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:8.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:9.04:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:10:*:*:*:*:*:*:*

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