CVE-2026-49807 Overview
CVE-2026-49807 is an information disclosure vulnerability in the Windows DirectX graphics subsystem. The flaw allows an authorized local attacker to read sensitive memory contents that should remain protected. Microsoft classifies the issue under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
The vulnerability affects Windows client and server platforms currently in mainstream support, including Windows 10, Windows 11, and Windows Server 2019 through 2025. Exploitation requires local access and provides no code execution capability, but leaked data may include memory addresses, cryptographic material, or process state useful in chained attacks.
Critical Impact
A local attacker can disclose sensitive DirectX-related memory contents without user interaction, enabling follow-on privilege escalation or sandbox escape attacks.
Affected Products
- Microsoft Windows 10 (1809, 21H2, 22H2) — x86, x64, ARM64
- Microsoft Windows 11 (24H2, 25H2, 26H1) — x64 and ARM64
- Microsoft Windows Server 2019, 2022, and 2025
Discovery Timeline
- 2026-07-14 - CVE-2026-49807 published to the National Vulnerability Database
- 2026-07-16 - Last updated in NVD database
Technical Details for CVE-2026-49807
Vulnerability Analysis
The vulnerability resides in the Windows DirectX component, which provides graphics, media, and compute APIs used by user-mode applications and games. DirectX drivers and runtime libraries interact closely with kernel-mode graphics services through the dxgkrnl.sys and related drivers. A flaw in this data path exposes memory contents to unprivileged callers.
The issue is exploitable locally by any user account, including guest and standard users, without requiring interaction from a second user. Successful exploitation yields high confidentiality impact but does not modify system state or affect availability. Microsoft has not published detailed technical internals, consistent with its practice for information disclosure issues.
Root Cause
The root cause is improper handling of memory buffers within DirectX processing routines, resulting in exposure of data that the calling process is not authorized to view. This pattern typically stems from uninitialized memory reads, missing bounds checks on output buffers, or insufficient sanitization of kernel-to-user data transfers.
Attack Vector
An attacker must execute code locally on the target system. The attack requires no elevated privileges and no user interaction. A malicious application, script, or logged-in adversary can invoke the affected DirectX interface and retrieve sensitive information from process or kernel memory. Leaked data may then be used to defeat Address Space Layout Randomization (ASLR) or stage a subsequent privilege escalation exploit.
No public proof-of-concept code or in-the-wild exploitation has been reported. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Detection Methods for CVE-2026-49807
Indicators of Compromise
- Unexpected user-mode processes making high-frequency calls to DirectX device interfaces such as \\.\DXGKrnl or D3DKMT APIs
- Unsigned or newly introduced binaries loading d3d10.dll, d3d11.dll, or dxgi.dll outside normal graphics workloads
- Standard-user processes probing graphics kernel objects from non-graphical contexts such as command-line tools or scripts
Detection Strategies
- Monitor process creation events for unusual invocation of DirectX APIs by non-graphics applications, especially from user profile directories or temporary paths
- Correlate module loads of DirectX runtime DLLs with parent processes that have no legitimate rendering function
- Baseline normal DirectX activity per host and alert on deviations, such as service accounts or headless server processes invoking graphics interfaces
Monitoring Recommendations
- Enable Windows Defender Application Control or AppLocker policies to restrict which binaries may execute on servers where DirectX use is uncommon
- Ingest Sysmon Event ID 7 (image loaded) and Event ID 1 (process create) into a SIEM to correlate DirectX-related activity across the fleet
- Track patch compliance for the July 2026 Microsoft security updates across all affected Windows and Windows Server versions
How to Mitigate CVE-2026-49807
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft Security Update Guide for CVE-2026-49807 to all affected systems
- Prioritize patching multi-user systems, terminal servers, and virtual desktop infrastructure where local users are most likely to invoke the vulnerable interface
- Audit local account inventories and remove unnecessary interactive logon rights on servers
Patch Information
Microsoft has released fixes through its standard security update channel. Refer to the vendor advisory at the Microsoft Security Response Center for the specific KB article and package identifiers that map to each affected Windows and Windows Server release. Deploy the updates through Windows Update, WSUS, Microsoft Intune, or Configuration Manager per your standard change control process.
Workarounds
- No official workarounds are documented by Microsoft; applying the security update is the supported remediation
- Restrict local logon rights on servers and multi-tenant hosts to reduce the population of accounts able to trigger the flaw
- Enforce least privilege and application allowlisting to limit execution of untrusted binaries that could invoke DirectX APIs
# Verify patch installation status on a Windows host
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 10
# Query installed updates matching the July 2026 cumulative rollup
wmic qfe list brief /format:table
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
