CVE-2026-98749 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux-based systems that utilize the max3100 serial driver should assess exposure and apply the patch to prevent potential use-after-free issues.

Why it matters

CVE-2026-98749 is a use-after-free vulnerability in the Linux kernel max3100 serial driver. Defenders should verify kernel patch application, monitor system logs, and review SPI device binding procedures to prevent potential issues. Evidence is limited, and further verification is required to determine the full scope of the vulnerability.

• Verify kernel patch application to prevent use-after-free issues
• Monitor system logs for errors related to the max3100 serial driver
• Review SPI device binding and unbinding procedures to ensure proper shutdown

Technical summary

The Linux kernel vulnerability (CVE-2026-98749) is a use-after-free issue in the max3100 serial driver. The vulnerability occurs when the SPI device is unbound before resume, and the serial core does not call the shutdown function again, resulting in the timer remaining armed. This could lead to a use-after-free issue when the timer callback is executed. The issue was resolved by adding final timer teardown to max3100_remove() and using timer_shutdown_sync() to prevent a racing callback from re-arming it.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the kernel patch to ensure the max3100 serial driver is updated
• Verify that the SPI device is properly bound and unbound to prevent use-after-free issues
• Monitor system logs for any errors related to the max3100 serial driver
• Perform a thorough review of system configurations and SPI device binding procedures
• Verify that all necessary mitigations are in place for exposed systems
• Conduct regular security audits to identify potential vulnerabilities
• Track and document changes to the system and its components

Evidence notes

The issue was found by an in-house static analysis tool. The CVE record and NVD entry provide details on the vulnerability, but no additional information on exploitation or impact is available. Evidence is limited, and further verification is required to determine the full scope of the vulnerability. Defenders should verify kernel patch application, monitor system logs, and review SPI device binding procedures to prevent potential issues.

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.