CVE-2026-83498 – Windows Virtualization-Based Security (VBS) Enclave Elevation of Privilege Vulnerability

CVE-2026-83498 is an elevation of privilege vulnerability in Windows Virtualization-Based Security (VBS) Enclave caused by an untrusted pointer dereference. A local attacker with low privileges could potentially exploit the flaw to leak data from a target enclave or execute code within the context of that enclave. The vulnerability requires no user interaction and has low attack complexity.

CVSS Score: 7.8

SEVERITY: Critical

THREAT: The vulnerability threatens the isolation provided by Windows VBS Enclaves. Successful exploitation could allow an attacker to access information that should remain protected inside an enclave or execute code within the enclave’s trusted context. This creates a serious risk to systems that depend on VBS Enclaves to isolate sensitive workloads and security-critical data.

EXPLOITS: Microsoft reports that the vulnerability is not publicly disclosed and not currently exploited. The exploitability assessment is Exploitation Less Likely. The CVSS v3.1 metrics list exploit code maturity as Unproven. The available data does not confirm the existence of publicly available proof-of-concept exploit code.

TECHNICAL SUMMARY: CVE-2026-83498 affects Windows Virtualization-Based Security Enclaves and is caused by an untrusted pointer dereference. The issue can occur when enclave-related code dereferences a pointer that cannot be fully trusted, potentially allowing an authorized local attacker to influence memory access in an unsafe manner. Exploitation requires local access and low privileges, has low attack complexity, and requires no user interaction. A successful attacker could potentially leak sensitive information from the target enclave or execute code within the security context of that enclave. The CVSS v3.1 metrics indicate high potential impact to confidentiality, integrity, and availability.

EXPLOITABILITY: Affected products include Windows 11 versions 23H2, 24H2, 25H2, and 26H1 on supported x64 and ARM64 platforms, as well as Windows Server 2025 and Windows Server 2025 Server Core installations. Exploitation requires local access with low privileges and does not require user interaction.

BUSINESS IMPACT: VBS Enclaves are designed to protect sensitive code and data from less-trusted parts of the operating system. A vulnerability that allows enclave data leakage or code execution could weaken this protection and expose information that organizations expect to remain isolated. Successful exploitation could compromise sensitive workloads, reduce trust in protected execution environments, and increase the impact of an existing local compromise.

WORKAROUND: No specific workaround is confirmed in the available data. Microsoft identifies an official fix as the remediation. If immediate patching is not possible, organizations should minimize untrusted local code execution and tightly restrict access to systems that rely on VBS Enclave protections.

URGENCY: This vulnerability is rated Critical and affects a security boundary designed to protect highly sensitive workloads. Although Microsoft reports no known exploitation and assesses exploitation as less likely, successful exploitation could expose protected enclave data or allow code execution inside the target enclave. Organizations using VBS Enclaves should prioritize deployment of the available security updates.