CVE-2026-98455 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Bluetooth protocol implementers, Linux system administrators responsible for applying kernel patches and ensuring system security, and security teams responsible for vulnerability management and risk assessment. They should assess exposure and prioritize patching to prevent potential exploitation.

Why it matters

This vulnerability in the Linux kernel's Bluetooth RFCOMM implementation can lead to system crashes, potential elevation of privileges, and increased risk of DoS attacks. Linux kernel developers, maintainers, and system administrators should assess exposure and prioritize patching to prevent potential exploitation.

• Potential system crashes or instability due to NULL pointer dereferences
• Possible elevation of privileges or unauthorized access to sensitive data
• Increased risk of denial-of-service (DoS) attacks
• Need for thorough verification of kernel versions and applied patches

Technical summary

The Linux kernel's Bluetooth RFCOMM implementation has a vulnerability that can cause a NULL pointer dereference. The issue arises when the getsockopt function is called with the RFCOMM_CONNINFO option on a socket that has been accepted but not yet fully set up. This can happen due to a race condition between the setup of a Bluetooth RFCOMM connection and the getsockopt call. The vulnerability can lead to system crashes, potential elevation of privileges, and increased risk of DoS attacks. The issue is caused by a NULL pointer dereference in the rfcomm_sock_getsockopt function.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the provided kernel patches to fix the vulnerability
• Ensure that all Linux kernel versions in use are up-to-date with the latest security patches
• Monitor system logs for potential exploitation attempts
• Perform thorough verification of kernel versions and applied patches
• 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 vulnerability was introduced due to a race condition between the setup of a Bluetooth RFCOMM connection and the getsockopt call with the RFCOMM_CONNINFO option. When a disconnect occurs, the session can be cleared while the deferred setup flag remains set, leading to a NULL pointer dereference.

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.