CVE-2026-98742 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux-based systems. These stakeholders should be aware of the vulnerability and take necessary steps to verify system configurations and apply kernel patches to prevent potential exploitation.

Why it matters

A vulnerability in the Linux kernel's ALSA sequencer subsystem requires verification of system configurations and kernel patches to prevent potential use-after-free errors and system instability.

• Potential use-after-free errors may occur due to concurrent compat CREATE_PORT requests.
• System crashes or instability may result from exploitation of this vulnerability.
• Verification of system configurations and kernel patches is necessary to prevent exploitation.

Technical summary

The Linux kernel's ALSA sequencer subsystem does not properly serialize compat port-info ioctls, allowing concurrent requests to pass the port-count check and potentially leading to a use-after-free vulnerability. This issue arises from the lack of proper serialization in the compat port-info ioctl path, which can result in the computation of an integer port index that exceeds the address field range and wraps to an existing index. The vulnerability requires verification of system configurations and kernel patches to prevent potential

Defensive priority

Medium

Recommended defensive actions

• Review and apply the provided kernel patches to ensure the ALSA sequencer subsystem is properly serialized.
• Monitor system logs for potential use-after-free errors.
• Verify system configurations to prevent concurrent compat CREATE_PORT requests.
• Perform a thorough review of the system configurations and apply patches to prevent exploitation.
• 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 information on the vulnerability, but details on exploitation, impact, and remediation are limited. There is a need for explicit evidence-limit language and defensive verification tasks rather than invented vulnerability facts. The Linux kernel's ALSA sequencer subsystem does not properly serialize compat port-info ioctls, allowing concurrent requests to pass the port-count check and potentially leading to a use-after-free vulnerability. The vulnerability requires verification of system

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.