OTPulse

Windows SMB Client Information Disclosure Vulnerability

MonitorCVSS 6.5CVE-2026-62782Aug 11, 2026
Microsoft
IT in OT - Windows Server and Active Directory are widely deployed in OT environments
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionRequired
Summary

Out-of-bounds read in Windows SMB Client allows an unauthorized attacker to disclose information over a network.

What this means
What could happen
An attacker could read sensitive information from memory on affected Windows systems by crafting malicious SMB responses, potentially exposing credentials or configuration data without authentication.
Who's at risk
Windows 10 (all versions 1607–22H2) and Windows 11 (all versions 23H2–26H1) systems, Windows Server 2016, 2019, 2022, and 2025 installations. This affects IT workstations, engineering workstations connected to industrial networks, and any Windows-based HMI or SCADA historian systems that act as SMB clients.
How it could be exploited
An attacker sends a specially crafted SMB message to a Windows computer running the vulnerable SMB client. The client processes the malformed message without proper bounds checking, allowing the attacker to read adjacent memory and extract sensitive information.
Prerequisites
  • Network access to SMB client ports (typically 139/445)
  • Ability to intercept or respond to SMB connections from the target system
  • User interaction to trigger SMB connection to attacker-controlled or compromised SMB server
remotely exploitableno authentication requiredlow complexityaffects Windows engineering workstations and domain controllers
Exploitability
Unlikely to be exploited — EPSS score 0.9%
Affected products (26)
26 with fix
ProductAffected VersionsFix Status
Windows 10 Version 1809 for 32-bit SystemsAll versionsBuild 10.0.17763.9115
Windows 10 Version 1809 for x64-based SystemsAll versionsBuild 10.0.17763.9115
Windows Server 2019All versionsBuild 10.0.17763.9115
Windows Server 2019 (Server Core installation)All versionsBuild 10.0.17763.9115
Windows Server 2022All versionsBuild 10.0.20348.5499
Remediation & Mitigation
0/3
Do now
0/1
WORKAROUNDRestrict network access to SMB ports (139, 445) to trusted internal networks only using firewall rules
Schedule — requires maintenance window
0/2

Patching may require device reboot — plan for process interruption

HOTFIXApply the August 2026 Windows security update to all affected systems
HARDENINGDisable SMB v1 on all systems that do not require legacy SMB compatibility
View full vendor advisory
API: /api/v1/advisories/76041cc0-0774-4c31-b3a0-159ac1d14b61

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Windows SMB Client Information Disclosure Vulnerability | CVSS 6.5 - OTPulse