CVE-2026-99187
Description
A flaw was found in the Linux kernel. During Central Processing Unit (CPU) hotplug operations, the Performance Monitoring Unit (PMU) context migration prematurely stops processing event groups after removing a leader, leaving active events running on the departing processor. A local user running performance monitoring events during CPU reconfiguration can trigger this flaw, leading to unexpected kernel behavior and potential system crashes that result in a Denial of Service (DoS).
Statement
This vulnerability is rated as having a Moderate impact because an attacker must possess local system access and coincide monitoring activity with runtime CPU hotplugging, limiting practical exploitability. On typical Red Hat Enterprise Linux deployments, dynamic processor offlining or addition is an infrequent administrative or virtualization event rather than a routine user-facing action. Although an incomplete event migration can trigger kernel instability or a denial of service, exploitation cannot be performed remotely and does not lead to privilege escalation or data confidentiality compromise.
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)
Other,Confidentiality,Integrity
Technical Impact: Other; Read Application Data; Modify Application Data; DoS: Resource Consumption (Other)
It is possible to overflow the number of temporary files because directories typically have limits on the number of files allowed. This could create a denial of service problem.
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