CVE-2026-43045 Linux CVE debrief

Who should care

Linux kernel maintainers, users, and administrators who manage Linux systems, especially those using affected kernel versions, should assess exposure and apply patches. This includes reviewing system configurations, ensuring proper accounting for pinned pages in the mshv module, and monitoring for potential memory corruption and page reference leaks. Additionally, defenders should verify if their Linux kernel versions are affected and apply patches or seek

Why it matters

A vulnerability in the Linux kernel's mshv module requires attention from maintainers and users to prevent potential memory corruption and page reference leaks by applying available patches.

• Memory corruption could occur due to partially pinned regions being used.
• Page reference leaks may happen when an error occurs mid-loop.
• Defenders should verify if their Linux kernel versions are affected and apply patches.
• Exposure assessment and patch application are crucial for system security.

Technical summary

The Linux kernel's mshv module had a vulnerability due to improper error handling in the mshv_region_pin function. This could result in memory corruption and page reference leaks. The issue arises from treating short pin counts as success and not properly accounting for already pinned pages during error handling. Patches are available in the Linux kernel source tree to fix this vulnerability. Affected versions include Linux kernel versions from 6.15 up to but not including 6.19.12, and specific release candidates for version 7.0.

Defensive priority

Medium priority for Linux kernel maintainers and users, especially those using affected versions, to apply patches and assess exposure.

Recommended defensive actions

• Assess exposure by checking if your Linux kernel version falls within the affected range.
• Apply patches provided in the Linux kernel source tree to fix the vulnerability.
• Review system configurations and ensure proper accounting for pinned pages in the mshv module.
• Monitor for potential memory corruption and page reference leaks.
• Verify if Linux kernel versions used in your systems are affected.
• Perform a thorough review of system configurations.
• Track the status of patch application and system security.

Evidence notes

The CVE and NVD records provide details on the vulnerability, its impact, and affected versions. Patches are available in the Linux kernel source tree. To verify, defenders should check the Linux kernel versions used in their systems, specifically versions from 6.15 up to but not including 6.19.12, and certain release candidates for version 7.0. They should confirm if their deployments are affected and apply patches or mitigations as necessary. Additionally, reviewing system configurations and ensuring proper accounting for pinned in

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.