CVE-2026-99168
mshv_vtl: Check per-CPU register page before mmap
Description
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.
INFO
Published Date :
Oct. 28, 2026, 11:17 a.m.
Last Modified :
Oct. 28, 2026, 11:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the Linux kernel patch.
- Ensure per-CPU register pages are validated.
- Return VM_FAULT_SIGBUS if page is absent.
- Check the selected per-CPU register page.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-99168.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/5c0757b065fbd140d8fbd05dc2c2146b713dfa68 | |
| https://git.kernel.org/stable/c/874194a8de75fc2f4d1fb70c670b289b7e48f93e |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-99168 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-99168
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-99168 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-99168 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 28, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99168.json">CVE-2026-99168</a> Added Reference https://git.kernel.org/stable/c/5c0757b065fbd140d8fbd05dc2c2146b713dfa68 Added Reference https://git.kernel.org/stable/c/874194a8de75fc2f4d1fb70c670b289b7e48f93e