CVE-2026-23432 mshv: Fix use-after-free in mshv_map_user_memory error path

What is CVE-2026-23432?

CVE-2026-23432 is a high-severity use after free vulnerability in Linux kernel, published on 3 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

Weakness: CWE-416

Which versions are affected by CVE-2026-23432?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23432?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2026-23432 being exploited?

There is no known exploitation of CVE-2026-23432 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-23432, GHSA-cxhx-54f3-q38v, UBUNTU-CVE-2026-23432.