CVE-2026-83776 in Windows
Summary
by MITRE • 10/14/2026
Out-of-bounds read in Microsoft Bluetooth Driver allows an unauthorized attacker to elevate privileges with a physical attack.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified as an out-of-bounds read within the Microsoft Bluetooth driver represents a critical memory safety flaw that can be exploited by an attacker with local access or, more critically, through proximity-based attacks leveraging the wireless nature of the protocol. This specific type of error occurs when the software reads data from a memory location outside the intended buffer boundary, typically due to insufficient validation of input parameters or incorrect calculation of array indices during Bluetooth stack processing operations. In the context of Windows operating systems, the Bluetooth driver operates at a high privilege level within the kernel space, meaning that any exploitation of this flaw grants the attacker direct access to sensitive system memory structures and potentially arbitrary code execution capabilities with SYSTEM-level privileges.
From a technical perspective, out-of-bounds reads are classified under CWE-125 in the Common Weakness Enumeration standard, which denotes reading data beyond the end or before the beginning of a buffer. While traditionally considered less severe than write vulnerabilities because they do not directly allow memory corruption, modern exploitation techniques often leverage information disclosure to bypass security mitigations such as Address Space Layout Randomization (ASLR). By leaking kernel pointers and other internal state information through these unintended reads, an attacker can construct reliable exploit chains that lead to arbitrary code execution. The physical attack vector mentioned in the description highlights a unique risk profile where proximity is sufficient for exploitation, allowing adversaries to target devices without needing prior network access or user interaction beyond being within Bluetooth range.
The operational impact of this vulnerability is severe, primarily centered on privilege escalation and potential system compromise. An unauthorized attacker who successfully exploits this flaw can elevate their privileges from a standard user account to that of the SYSTEM administrator. This level of access allows for complete control over the affected device, including the ability to install programs, view, change, or delete data, and create new accounts with full administrative rights. Furthermore, because Bluetooth drivers often handle sensitive pairing information and connection states, exploitation could also lead to privacy violations through unauthorized access to personal files, communication logs, and other confidential data stored on the compromised system. The physical nature of the attack vector makes it particularly dangerous in environments where devices are left unattended or accessible to malicious actors in public spaces.
Mitigation strategies for this vulnerability primarily involve applying the latest security updates provided by Microsoft, which patch the underlying memory management errors within the Bluetooth driver stack. Organizations should ensure that all endpoints are configured with automatic Windows Update settings enabled to receive critical and important patches promptly. Additionally, implementing strict physical access controls can reduce the risk of proximity-based attacks, although this is often impractical in mobile or public scenarios. Users should also consider disabling Bluetooth when not in use if it poses a significant threat vector in their specific environment, though this may impact functionality. From an architectural standpoint, enabling hardware-enforced stack protection features such as Kernel Mode Code Integrity and Data Execution Prevention can help mitigate the exploitation of memory corruption vulnerabilities by preventing the execution of malicious code injected into kernel space.
This vulnerability aligns with several tactics within the MITRE ATT&CK framework, particularly those related to privilege escalation and defense evasion through information discovery. The out-of-bounds read facilitates reconnaissance activities that allow attackers to map system internals before executing further malicious actions. Security teams should monitor for anomalous behavior in Bluetooth driver processes and look for indicators of compromise associated with kernel-level exploitation attempts. Regular vulnerability assessments focusing on peripheral drivers and wireless communication stacks are essential components of a robust security posture, ensuring that legacy or less scrutinized code paths do not become entry points for sophisticated attacks.