CVE-2026-23432
Received Received - Intake
Use-After-Free in Linux mshv_map_user_memory Causes Kernel Panic

Publication date: 2026-04-03

Last updated on: 2026-04-27

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: mshv: Fix use-after-free in mshv_map_user_memory error path In the error path of mshv_map_user_memory(), calling vfree() directly on the region leaves the MMU notifier registered. When userspace later unmaps the memory, the notifier fires and accesses the freed region, causing a use-after-free and potential kernel panic. Replace vfree() with mshv_partition_put() to properly unregister the MMU notifier before freeing the region.
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Meta Information
Published
2026-04-03
Last Modified
2026-04-27
Generated
2026-06-16
AI Q&A
2026-04-03
EPSS Evaluated
2026-06-15
NVD
CVE-2026-23432
EUVD
EUVD-2026-18669
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 6.19
linux linux_kernel From 6.19.1 (inc) to 6.19.10 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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Executive Summary

This vulnerability is a use-after-free issue in the Linux kernel's mshv_map_user_memory function. Specifically, when an error occurs, the code calls vfree() directly on a memory region without properly unregistering the MMU notifier. Later, when userspace unmaps this memory, the still-registered notifier accesses the already freed memory region, leading to a use-after-free condition that can cause a kernel panic.

The fix involves replacing the direct call to vfree() with mshv_partition_put(), which correctly unregisters the MMU notifier before freeing the memory region, preventing the use-after-free scenario.

Impact Analysis

This vulnerability can lead to a kernel panic due to a use-after-free condition in the Linux kernel. A kernel panic can cause the system to crash or become unstable, potentially leading to denial of service. This could disrupt normal operations and affect system availability.

Mitigation Strategies

The vulnerability is fixed by replacing the direct call to vfree() with mshv_partition_put() in the mshv_map_user_memory() function to properly unregister the MMU notifier before freeing the memory region.

To mitigate this vulnerability immediately, you should update your Linux kernel to a version that includes this fix.

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