Linux Kernel up to 7.2.12 mshv_vtl mshv_vtl_fault null pointer dereference

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 7.2.12. This impacts the function mshv_vtl_fault of the component mshv_vtl. Such manipulation leads to null pointer dereference. This vulnerability is listed as CVE-2026-99168. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.2.12. Affected by this issue is the function mshv_vtl_fault of the component mshv_vtl. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Check per-CPU register page before mmap Register-page setup is optional for each CPU. If allocation or registration fails, mshv_vtl_configure_reg_page() warns and leaves that CPU's reg_page NULL, but initial context setup continues successfully. Meanwhile, successful setup on another CPU sets the global mshv_has_reg_page flag. mshv_vtl_fault() checks this global flag before selecting the requested CPU's register page. With mixed setup results across online CPUs, the check passes even for a CPU with no register page, reaching get_page(NULL) when userspace faults in that mapping. Check the selected per-CPU register page before taking its reference and return VM_FAULT_SIGBUS if it is absent.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-99168 since 09/25/2026. The exploitation is known to be easy. The attack may be launched remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/28/2026).

Upgrading to version 7.2.13 eliminates this vulnerability. Applying the patch 5c0757b065fbd140d8fbd05dc2c2146b713dfa68 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.2.10
• 7.2.11
• 7.2.12

License

• open-source

Website

• Vendor: https://www.kernel.org/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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