How severe is CVE-2021-4032?

CVE-2021-4032 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-4032 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4032?

CVE-2021-4032 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-2021-4032?

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

When was CVE-2021-4032 published?

CVE-2021-4032 was published on 2022-01-21 and last updated on 2026-06-17.

CVE-2021-4032

CVE-2021-4032 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 4.4. 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-459.

Key facts

Severity: Medium (CVSS 3.x base score 4.4)
CVSS v2: 4.9
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-459
Affected product: Linux Linux Kernel
Published: 2022-01-21
Last modified: 2026-06-17

Description

A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm_free_lapic when a failure allocation was detected. In this flaw the KVM subsystem may crash the kernel due to mishandling of memory errors that happens during VCPU construction, which allows an attacker with special user privilege to cause a denial of service. This flaw affects kernel versions prior to 5.15 rc7.

Frequently asked questions

What is CVE-2021-4032?: A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm_free_lapic when a failure allocation was detected. In this flaw the KVM subsystem may crash the kernel due to mishandling of memory errors that happens during VCPU construction, which allows an attacker with special user privilege to cause a denial of service. This flaw affects kernel versions prior to 5.15 rc7.
How severe is CVE-2021-4032?: CVE-2021-4032 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-4032 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4032?: CVE-2021-4032 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-2021-4032?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-4032 published?: CVE-2021-4032 was published on 2022-01-21 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*

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