CVE-2026-99178
Description
A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem. When an asynchronous page fault is interrupted by a Non-Maskable Interrupt (NMI) that also encounters a page fault, the kernel improperly clears the pending fault status flags belonging to the interrupted handler. A local user can trigger this condition, causing the guest kernel to panic and resulting in a Denial of Service (DoS).
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Application Data; Modify Memory; DoS: Crash, Exit, or Restart; Execute Unauthorized Code or Commands
Attackers may be able to exploit a signal handler race condition to cause the product state to be corrupted. It may be possible to execute arbitrary code by modifying global variables or data structures at unexpected times, violating the assumptions of code that uses this global data.
Access Control
Technical Impact: Gain Privileges or Assume Identity
If a signal handler interrupts code that is executing with privileges, it may be possible that the signal handler will also be executed with elevated privileges, possibly making subsequent exploits more severe.
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