CVE-2026-99015 Linux CVE debrief

Who should care

Linux kernel developers, maintainers, and users who rely on Bluetooth HCI sockets should assess their exposure to this vulnerability and apply patches or mitigations as needed. This includes operators managing Linux kernel deployments, platform administrators, vulnerability management teams, and security teams responsible for monitoring and mitigating potential threats.

Why it matters

This vulnerability requires attention from Linux kernel developers, maintainers, and users who rely on Bluetooth HCI sockets. Patches have been provided to resolve the issue, and users should verify their exposure and apply mitigations as needed.

• Potential NULL pointer dereference or use-after-free
• Race condition between hci_sock_bind and send_monitor_control_replay functions
• Requires verification of HCI socket rebinding and detachment

Technical summary

The Linux kernel vulnerability CVE-2026-99015 is related to the Bluetooth HCI socket implementation. A race condition exists between the `hci_sock_bind` function and the `send_monitor_control_replay` function, which can lead to a NULL pointer dereference or use-after-free. The vulnerability has been resolved through a series of commits that ensure proper serialization of dead-device detachment. This issue requires attention from Linux kernel developers, maintainers, and users who rely on Bluetooth HCI sockets. Patches have been provided to resolve the issue, and users should verify their exposure and apply mitigations as needed.

Defensive priority

Medium

Recommended defensive actions

• Review and apply patches from Linux kernel maintainers
• Verify HCI socket rebinding and detachment in Linux kernel
• Monitor Linux kernel updates for potential vulnerabilities
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and references to patches. However, there is limited information on potential exploits or attacks.

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.