CVE-2026-64126 Linux CVE debrief

Who should care

System administrators and security teams managing Linux kernel-based systems, especially those with Bluetooth functionality enabled, should be aware of this vulnerability. The vulnerability's impact is limited to systems with specific network administration capabilities. These teams should review the official advisory and CVE record to validate affected scope, severity, and vendor guidance.

Technical summary

The Linux kernel's Bluetooth MGMT subsystem has a vulnerability in the handling of the MGMT_OP_ADD_EXT_ADV_DATA command. This command is designed to add extended advertising data but does not properly validate the length of the provided data. As a result, an attacker with CAP_NET_ADMIN privileges in the initial user namespace can trigger a slab-out-of-bounds read. This could potentially allow for the disclosure of sensitive information. The vulnerability is due to a lack of proper length validation, which can lead to out-of-bounds data access.

Defensive priority

Medium-High due to potential for sensitive data disclosure and limited attack surface requiring CAP_NET_ADMIN privileges in the initial user namespace. However, the actual priority may vary depending on the specific use case and system configuration. It is essential to assess the potential impact on the organization and prioritize accordingly. Implementing additional access controls and validation for MGMT_OP_ADD_EXT_ADV_DATA commands can help mitigate the vulnerability. Furthermore, monitoring system logs for suspicious Bluetooth activity can aid in detecting potential attacks. Restricting CAP_NET_ADMIN privileges to necessary users only can also help reduce the attack surface. Applying the official patch or updating to a fixed version of the Linux kernel is recommended to address this vulnerability effectively. Compensating controls, such as network segmentation and access controls, can be implemented to reduce the impact of the vulnerability. Asset inventory and source tracking can help identify and prioritize affected systems. Rollback/change windows can be used to manage the deployment of patches and updates. Exposure review and monitoring can aid in detecting and responding to potential attacks. Vendor patch guidance should be followed to ensure the vulnerability is properly addressed. By taking these steps, organizations can effectively manage the risk associated with this vulnerability and protect their systems from potential attacks. The implementation of these defensive measures can help prevent exploitation and minimize the impact of the vulnerability. Therefore, it is crucial to prioritize and address this vulnerability in a timely and effective manner. The recommended actions are essential to mitigate the vulnerability and protect the organization's systems and data. By following these recommendations, organizations can ensure the security and integrity of their systems and data. The vulnerability requires attention from system administrators and security teams to ensure that the necessary measures are taken to prevent exploitation and minimize the impact of the vulnerability. The implementation of defensive measures can help prevent attacks and保护组织

Recommended defensive actions

• Apply the official patch or update to a fixed version of the Linux kernel.
• Restrict CAP_NET_ADMIN privileges to necessary users only.
• Monitor system logs for suspicious Bluetooth activity.
• Implement additional access controls and validation for MGMT_OP_ADD_EXT_ADV_DATA commands.
• Perform exposure review to identify potential attack surfaces.
• Conduct asset inventory to track affected systems.
• Use rollback/change windows to manage patch deployment.

Evidence notes

The CVE record was published on 2026-07-19T16:17:54.260Z and has not been modified since then. The NVD entry is currently Received. Multiple source references are provided, including links to the Linux kernel stable repository. However, the current information available is limited, and further verification is needed to confirm the affected scope and severity. Defenders should verify the official advisory and CVE record for more details.

Official resources