CVE-2026-64374 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel deployments, especially those with high-traffic or real-time systems, should assess exposure and prioritize patching vulnerable versions to prevent potential system slowdowns and latency issues.

Why it matters

CVE-2026-64374 is a Linux kernel vulnerability that causes a live lock issue on non-PREEMPT_RT systems, leading to high latency and system slowdowns. Defenders should prioritize patching vulnerable versions to prevent potential issues.

• System slowdowns and high latency under heavy workloads
• Potential for live lock issues on non-PREEMPT_RT systems
• Need for patching vulnerable Linux kernel versions to prevent issues

Technical summary

The Linux kernel vulnerability CVE-2026-64374 causes a live lock issue on non-PREEMPT_RT systems due to the RT_PUSH_IPI logic. This results in high latency and system slowdowns under heavy workloads with softirqs and RT tasks. The fix involves making RT_PUSH_IPI default off for non-PREEMPT_RT systems. The vulnerability affects Linux kernel deployments, especially those with high-traffic or real-time systems. Defenders should prioritize patching vulnerable versions to prevent potential system slowdowns and latency issues.

Defensive priority

Defenders should prioritize patching vulnerable Linux kernel versions to prevent potential system slowdowns and latency issues.

Recommended defensive actions

• Patch vulnerable Linux kernel versions
• Inventory and assess exposure of Linux kernel deployments
• Monitor system performance for latency and slowdown issues
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The issue arises from the RT_PUSH_IPI logic, which was created to help PREEMPT_RT but could cause problems on non-PREEMPT_RT systems. The fix involves making RT_PUSH_IPI default off for non-PREEMPT_RT systems.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.