CVE-2026-64374
Description
A flaw was found in the Linux kernel's real-time (RT) scheduler. In non-real-time configurations, the RT_PUSH_IPI mechanism, designed to improve task migration, can lead to a live lock. This occurs when a CPU handling heavy network traffic is repeatedly interrupted by other CPUs attempting to schedule waiting real-time tasks. The continuous interruptions prevent the CPU from processing tasks, resulting in a Denial of Service (DoS) for that CPU.
Statement
This vulnerability is rated as Moderate impact because triggering the condition requires a specific concurrency scenario involving high softirq activity alongside real-time task scheduling, resulting in a localized denial of service rather than code execution or privilege escalation. Under non-PREEMPT_RT enterprise environments running multi-core systems, heavy workloads such as sustained network traffic can cause cross-CPU inter-processor interrupts to starve lower-priority execution threads and induce a live lock. Red Hat Enterprise Linux 8 kernels contain this scheduling mechanism, whereas releases such as Red Hat Enterprise Linux 9 and 10 are unaffected.
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 | 5.5 | N/A | 7.5 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
