CVE-2026-83501
Summary
by MITRE • 09/08/2026
Out-of-bounds read in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified involves a critical out-of-bounds read flaw within the Windows Virtualization-Based Security enclave subsystem, specifically affecting components responsible for managing secure enclaves such as those used by Intel Software Guard Extensions or AMD Secure Encrypted Virtualization implementations integrated into the Windows operating system. This architectural component is designed to isolate sensitive data and code from the rest of the system, including the host operating system kernel and other applications, thereby providing a high-assurance environment for processing confidential information. The flaw arises when the enclave runtime fails to properly validate memory access boundaries during specific operations, allowing an attacker who has already gained local execution privileges within a user context or potentially through privilege escalation vectors to trigger a read operation that accesses memory locations outside the allocated buffer space of the enclave. This type of error is classified under CWE-125, which describes out-of-bounds read vulnerabilities where software reads data past the end or before the beginning of the intended buffer, leading to the disclosure of sensitive information contained in adjacent memory regions.
From an operational perspective, this vulnerability poses a significant risk because it undermines one of the core security guarantees provided by Virtualization-Based Security. By exploiting this out-of-bounds read condition, an authorized attacker can potentially leak cryptographic keys, session tokens, or other high-value secrets that are stored within the enclave's protected memory space. Since VBS enclaves are often utilized to protect credentials and sensitive user data even from administrators with local access, bypassing these protections represents a severe degradation of system security posture. The attack vector is classified as Local in terms of initial access requirements but may involve Privilege Escalation if the attacker needs elevated rights to interact with specific enclave management APIs or kernel structures that facilitate the exploit. In the MITRE ATT&CK framework, this activity aligns with techniques related to Memory Dumping and potentially Credential Access, specifically targeting protected memory regions that are typically considered inaccessible through standard application interfaces.
The impact of such a vulnerability extends beyond simple data leakage; it can lead to full system compromise if the disclosed information includes keys used for further encryption or authentication processes within the enterprise environment. Attackers could use this leaked data to impersonate users, decrypt stored sensitive files, or bypass multi-factor authentication mechanisms that rely on secure enclave storage. Furthermore, because VBS operates at a higher privilege level than standard user applications but below the hypervisor itself, successful exploitation can provide insights into kernel memory layouts and other security mitigations like Kernel Patch Protection, thereby facilitating more advanced attacks against deeper system components. The presence of this flaw indicates a failure in boundary checks during memory management operations within the enclave runtime, which should strictly enforce isolation boundaries to prevent any form of side-channel or direct memory access that could reveal internal state information.
Mitigation strategies primarily involve applying the latest security updates provided by Microsoft, which typically include patches that correct the buffer validation logic and enhance bounds checking mechanisms within the VBS subsystem administrators must ensure that their systems are fully patched with the relevant cumulative update packages to address this specific flaw. Additionally, organizations should enforce strict access controls on local accounts to minimize the attack surface for potential privilege escalation attempts that could lead to exploitation of this vulnerability. Enabling all available virtualization-based security features and ensuring hardware support is correctly configured can help maintain the integrity of enclave operations. Regular auditing of system logs for unusual memory access patterns or unauthorized interactions with secure enclaves may also aid in detecting attempted exploits before they result in significant data loss, while adhering to least privilege principles ensures that even if an attacker gains local access, their ability to interact with high-security components remains restricted and monitored effectively.