CVE-2026-62786

This vulnerability is a “read the wrong memory” bug in a Windows graphics component. If someone already has a foothold on the same computer, they may be able to peek at sensitive information stored in memory—like pieces of data used by Windows and applications—without crashing the system.

This matters if you run Windows 10, Windows 11, or Windows Server 2012/2012 R2/2016/2019/2022/2025 on machines where a low-privilege attacker could run code. The risk is tied to local access: an attacker typically needs to be able to execute something on your machine first, then trigger the bug to read protected memory. This is only a concern when it’s reachable from that local attacker position (i.e., not from anonymous remote access on its own).

Treat this as urgent (RED) because it’s a kernel-level information disclosure that helps an attacker steal data after gaining some local execution capability. The August 2026 Patch Tuesday activity and threat-actor reporting (Lazarus group) increase the chance that real-world adversaries may target this kind of Windows memory disclosure.

1. Identify affected systems

   • For each endpoint and server, record: OS edition (Windows 10/11 or which Windows Server), and the current build number.
   • Build number is typically shown in Settings → System → About (Windows clients) or via OS build reporting tools.

2. Check against the fixed build list

   • Windows 10 is fixed when your build is one of:
     • 10.0.14393.9418
     • 10.0.17763.9115
     • 10.0.19044.7663
     • 10.0.19045.7663
   • Windows 11 is fixed when your build is one of:
     • 10.0.22631.7517
     • 10.0.26100.9106
     • 10.0.26200.9106
     • 10.0.28000.2704
   • Windows Server is fixed when your build is one of:
     • Windows Server 2012/2012 R2/2016: 10.0.14393.9418
     • Windows Server 2019: 10.0.17763.9115
     • Windows Server 2022: 10.0.20348.5440
     • Windows Server 2025: 10.0.26100.33222

3. Patch (recommended path)

   • Apply the Microsoft update that includes CVE-2026-62786 for your specific OS/version.
   • Use the Microsoft Update Guide entry for this CVE to ensure the correct patch is installed: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62786

4. Validate

   • Re-check the build number after patching and confirm it matches one of the fixed builds above.
   • Confirm Windows Update indicates the security update is installed.

5. If you cannot patch immediately (temporary containment)

   • Reduce the chance of an attacker ever getting local code execution by tightening endpoint access controls: least-privilege for users, and review/limit accounts that can run untrusted software.
   • Monitor for unusual local execution patterns (e.g., unexpected binaries launched with low-privilege users) and investigate promptly.
   • Prioritize patching on any server/endpoint that is exposed to frequent user activity or where attackers commonly gain initial access.

6. What to monitor after patching

   • Review security alerts related to attempts to execute or tamper with system components.
   • Track whether any suspicious sessions occurred around the time of patching (this helps confirm you’re not patching after an active intrusion).

CVE-2026-62786 is a CWE-125 (out-of-bounds read) in the Windows kernel graphics driver (Win32K). A local attacker with low privileges who can execute code on the system can exploit incorrect memory boundary handling to read confidential information from protected areas of memory. This is local and does not require user interaction. The affected scope includes Windows 10, Windows 11, and multiple Windows Server versions as listed, and Microsoft released fixed builds via the August 2026 Patch Tuesday update cycle; KEV listing was not found in the provided findings, and no public exploit code was reported. PULSE reporting associates this CVE with threat-actor activity (Lazarus group).