How severe is CVE-2026-43045?

CVE-2026-43045 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-43045 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43045?

CVE-2026-43045 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-43045?

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

Does CVE-2026-43045 have an EU (EUVD) identifier?

Yes. CVE-2026-43045 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26644.

When was CVE-2026-43045 published?

CVE-2026-43045 was published on 2026-05-01 and last updated on 2026-06-17.

CVE-2026-43045

CVE-2026-43045 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26644
Affected product: Linux Linux Kernel
Published: 2026-05-01
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: mshv: Fix error handling in mshv_region_pin The current error handling has two issues: First, pin_user_pages_fast() can return a short pin count (less than requested but greater than zero) when it cannot pin all requested pages. This is treated as success, leading to partially pinned regions being used, which causes memory corruption. Second, when an error occurs mid-loop, already pinned pages from the current batch are not properly accounted for before calling mshv_region_invalidate_pages(), causing a page reference leak. Treat short pins as errors and fix partial batch accounting before cleanup.

Frequently asked questions

What is CVE-2026-43045?: In the Linux kernel, the following vulnerability has been resolved: mshv: Fix error handling in mshv_region_pin The current error handling has two issues: First, pin_user_pages_fast() can return a short pin count (less than requested but greater than zero) when it cannot pin all requested pages. This is treated as success, leading to partially pinned regions being used, which causes memory corruption. Second, when an error occurs mid-loop, already pinned pages from the current batch are not properly accounted for before calling mshv_region_invalidate_pages(), causing a page reference leak. Treat short pins as errors and fix partial batch accounting before cleanup.
How severe is CVE-2026-43045?: CVE-2026-43045 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-43045 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43045?: CVE-2026-43045 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43045?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43045 have an EU (EUVD) identifier?: Yes. CVE-2026-43045 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26644.
When was CVE-2026-43045 published?: CVE-2026-43045 was published on 2026-05-01 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*

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