CVE-2026-57095 Overview
CVE-2026-57095 is an information disclosure vulnerability in the Windows Win32K subsystem that enables local privilege escalation. The flaw stems from exposure of sensitive kernel information to an unauthorized actor [CWE-200]. An authenticated local attacker can leverage the leaked data to elevate privileges on affected Windows and Windows Server systems.
The vulnerability affects the entire supported Windows lineup, from Windows 10 1607 through Windows 11 26H1, and Windows Server 2012 through Windows Server 2025. Microsoft published the advisory on July 14, 2026.
Critical Impact
A local, low-privileged attacker can exploit leaked kernel data to gain SYSTEM-level privileges, resulting in high impact to confidentiality, integrity, and availability.
Affected Products
- Microsoft Windows 10 (1607, 1809, 21H2, 22H2) on x86, x64, and ARM64 architectures
- Microsoft Windows 11 (24H2, 25H2, 26H1) on x64 and ARM64 architectures
- Microsoft Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025
Discovery Timeline
- 2026-07-14 - CVE-2026-57095 published to NVD
- 2026-07-14 - Microsoft releases security update for CVE-2026-57095
- 2026-07-20 - Last updated in NVD database
Technical Details for CVE-2026-57095
Vulnerability Analysis
The vulnerability resides in Win32K, the kernel-mode component that handles the Windows graphical subsystem, window management, and user-mode graphics device interface calls. Win32K executes in kernel context, so any information leak from this subsystem exposes privileged memory contents to user-mode callers.
An authenticated local attacker can trigger a code path in Win32K that returns sensitive kernel data to a user-mode process. Disclosed contents typically include kernel object addresses, pool metadata, or uninitialized stack and heap memory. These values are the primitives required to bypass Kernel Address Space Layout Randomization (KASLR) and stabilize follow-on kernel exploits.
Once KASLR is defeated, the attacker chains the disclosure with a separate memory corruption primitive to overwrite kernel structures such as the process token. This yields SYSTEM privileges and full control of the host.
Root Cause
The root cause maps to CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor). A Win32K syscall or callback returns kernel-controlled memory to user mode without adequately sanitizing or bounding the response buffer, leaking data that should remain confined to ring 0.
Attack Vector
Exploitation requires local access and low privileges (PR:L), with no user interaction. The attacker must be able to execute code on the target, typically via an existing foothold, a malicious application, or a compromised low-privilege service account. Remote exploitation is not possible without an initial access vector.
Microsoft has not disclosed detailed technical mechanics. Refer to the Microsoft Security Update for CVE-2026-57095 for authoritative guidance.
Detection Methods for CVE-2026-57095
Indicators of Compromise
- Unexpected child processes spawned by user-mode applications running as SYSTEM shortly after graphical subsystem calls
- Creation or modification of privileged services, scheduled tasks, or local administrator accounts by non-administrative users
- Anomalous process token replacements or handle duplications targeting lsass.exe or other SYSTEM-owned processes
Detection Strategies
- Monitor for local privilege escalation behaviors: sudden transitions from a medium-integrity process to SYSTEM without a legitimate elevation path
- Alert on unsigned or unusual binaries invoking large volumes of Win32K syscalls or NtUserCall variants
- Correlate abnormal kernel crash telemetry (win32kfull.sys, win32kbase.sys) with subsequent privilege changes on the same host
Monitoring Recommendations
- Enable Microsoft Defender ASR rules that block credential and process token abuse
- Ingest Windows Security, Sysmon, and kernel event logs into a centralized SIEM for cross-host correlation
- Baseline normal Win32K API usage per endpoint role and alert on statistical deviations
How to Mitigate CVE-2026-57095
Immediate Actions Required
- Apply the Microsoft July 2026 security update to all affected Windows and Windows Server systems without delay
- Prioritize patching multi-user systems, RDP hosts, VDI infrastructure, and Terminal Servers where multiple low-privilege users have interactive access
- Audit local user and service account privileges to reduce the pool of accounts capable of triggering local exploitation
Patch Information
Microsoft released a security update addressing CVE-2026-57095 on July 14, 2026. Consult the Microsoft Security Update Guide for CVE-2026-57095 for the specific KB article and cumulative update mapped to each affected Windows build.
Workarounds
- No official workarounds have been published by Microsoft; patching is the required remediation
- Restrict interactive and remote logon rights to trusted administrative personnel until updates are deployed
- Apply application allowlisting (Windows Defender Application Control or AppLocker) to block execution of unauthorized binaries that could weaponize the flaw
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
