CVE-2026-42982 Overview
CVE-2026-42982 is a local privilege escalation vulnerability in Windows Secure Kernel Mode. The flaw stems from improper validation of consistency within input, classified under [CWE-1288]. An authorized local attacker can exploit this weakness to elevate privileges on affected Windows client and server systems.
Microsoft published the advisory on July 14, 2026, covering supported Windows 10, Windows 11, and Windows Server releases. Successful exploitation compromises confidentiality, integrity, and availability at the highest impact level, giving attackers a path from a low-privileged account to code execution inside the trusted Secure Kernel environment.
Critical Impact
An authenticated local attacker can escape user-mode restrictions and gain SYSTEM-level privileges through the Secure Kernel Mode boundary, undermining Virtualization-Based Security (VBS) protections.
Affected Products
- Microsoft Windows 10 (1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (23H2, 24H2, 25H2, 26H1)
- Microsoft Windows Server 2016, 2019, 2022, and 2025
Discovery Timeline
- 2026-07-14 - CVE-2026-42982 published to NVD
- 2026-07-16 - Last updated in NVD database
Technical Details for CVE-2026-42982
Vulnerability Analysis
Secure Kernel Mode (SKM) is the trusted execution component of Windows Virtualization-Based Security. It runs at Virtual Trust Level 1 (VTL1) and enforces isolation from the normal-mode kernel at VTL0. The vulnerability arises when SKM accepts input from a lower trust boundary without verifying internal consistency between related fields.
An authorized local attacker can craft input that passes initial validation checks but produces inconsistent state when interpreted by downstream logic. This mismatch enables the attacker to influence Secure Kernel operations outside intended parameters. The result is code execution or data manipulation within a trust boundary that user-mode processes should never reach.
The attack requires local access and low privileges but no user interaction. Because Secure Kernel Mode protects credentials, Hypervisor-Protected Code Integrity (HVCI), and Credential Guard, a compromise weakens the entire VBS security model.
Root Cause
The root cause is mapped to [CWE-1288]: Improper Validation of Consistency within Input. Rather than a single missing bounds check, the flaw involves data structures where fields must maintain a defined relationship. SKM validates each field individually but fails to confirm the combined state is coherent, allowing contradictory inputs to reach privileged code paths.
Attack Vector
Exploitation requires an authenticated session on the target host. The attacker submits crafted input through an interface exposed to normal-mode callers that transitions into Secure Kernel Mode. No user interaction and no network access are needed, which makes this vulnerability attractive for post-compromise privilege escalation following initial access through phishing, malware, or valid credential abuse.
No public proof-of-concept exploit code is available in Exploit-DB, and CISA has not added CVE-2026-42982 to the Known Exploited Vulnerabilities catalog as of publication.
Detection Methods for CVE-2026-42982
Indicators of Compromise
- Unexpected token or privilege changes on processes that previously ran as a standard user, particularly transitions to SYSTEM or TrustedInstaller contexts.
- Anomalous crashes, bug checks, or event log entries referencing securekernel.exe, skci.dll, or VBS subsystems.
- Loading of unsigned or newly introduced drivers immediately following suspicious user-mode activity.
Detection Strategies
- Hunt for local privilege escalation behavior: standard user processes spawning administrative tools such as cmd.exe, powershell.exe, or net.exe with elevated tokens.
- Correlate Windows Event ID 4672 (special privileges assigned) with parent processes that do not normally hold administrative rights.
- Track Kernel-General and Kernel-Boot event logs for anomalies in secure kernel initialization or integrity check failures.
Monitoring Recommendations
- Enable audit policies for process creation with command line logging (Event ID 4688) across all Windows endpoints and servers.
- Forward Sysmon and Windows Security logs to a centralized analytics platform for behavioral correlation.
- Establish baselines for driver loads and monitor deviations, especially around VBS and HVCI components.
How to Mitigate CVE-2026-42982
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft Security Update Guide for CVE-2026-42982 across all affected Windows 10, Windows 11, and Windows Server systems.
- Prioritize patching on multi-user systems, jump hosts, and terminal servers where local privilege escalation exposure is highest.
- Restrict local logon rights to essential accounts and enforce least privilege on interactive workstations.
Patch Information
Microsoft has released fixes through its July 2026 security update cycle. Administrators should deploy the corresponding cumulative update for each supported build listed in the advisory. Verify patch installation using wmic qfe list or the Get-HotFix PowerShell cmdlet and confirm the KB identifier matches Microsoft's guidance for CVE-2026-42982.
Workarounds
- No official workaround has been published by Microsoft. Applying the security update is the required remediation.
- Reduce exposure by removing unnecessary local accounts and disabling interactive logon for service accounts until patching completes.
- Ensure Virtualization-Based Security, HVCI, and Credential Guard remain enabled to preserve defense-in-depth even where patch deployment is staged.
# Verify installation of the CVE-2026-42982 security update
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 10
# Confirm Virtualization-Based Security status
Get-CimInstance -ClassName Win32_DeviceGuard -Namespace root\Microsoft\Windows\DeviceGuard
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
