CVE-2026-97921 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux-based systems should assess exposure and apply patches for this vulnerability. The vulnerability affects the Linux kernel's tracing subsystem, which is used for performance analysis and debugging. The vulnerability allows an attacker to cause a memory leak, which could potentially lead to a denial of service. Users of Linux-based systems should review their systems for

Why it matters

A vulnerability in the Linux kernel's tracing subsystem can cause a memory leak when a histogram trigger with an invalid modifier is written. Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux-based systems should assess exposure and apply patches.

• Memory leak due to histogram field not being freed
• Potential denial of service due to resource exhaustion
• Need to verify Linux kernel versions for exposure
• Apply patches or updates to prevent exploitation

Technical summary

The Linux kernel's tracing subsystem has a vulnerability that occurs when a histogram trigger with an invalid modifier is written. This causes a memory leak of histogram fields. The issue has been fixed in the kernel. The vulnerability allows an attacker to cause a memory leak, which could potentially lead to a denial of service. The Linux kernel's tracing subsystem is used for performance analysis and debugging, and the vulnerability is difficult to exploit and requires knowledge of the Linux kernel's tracing subsystem.

Defensive priority

Assess exposure and apply patches for Linux kernel tracing vulnerabilities.

Recommended defensive actions

• Assess Linux kernel versions for exposure to CVE-2026-97921
• Apply patches or updates for Linux kernel tracing subsystem vulnerabilities
• Monitor system logs for suspicious tracing activity
• 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 CVE record and NVD entry provide details on the vulnerability, including its description and affected components. The Linux kernel's tracing subsystem is a complex system that allows developers to collect data on system performance and behavior. The vulnerability is caused by a memory leak in the histogram trigger, which can be exploited by an attacker to cause a denial of service. The vulnerability has been fixed in the kernel, and users are advised to apply patches or updates to prevent exploitation.

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.