OTPulse

Windows SMB Client Information Disclosure Vulnerability

MonitorCVSS 5.7CVE-2026-69572Sep 8, 2026
Microsoft
IT in OT - Windows Server and Active Directory are widely deployed in OT environments
Attack path
Attack VectorNetwork
Auth RequiredLow
ComplexityLow
User InteractionRequired
Summary

Out-of-bounds read vulnerability in Windows SMB Client allows an authenticated attacker to disclose sensitive information over the network. The vulnerability affects Windows 10 (versions 1607, 1809, 21H2, 22H2), Windows 11 (versions 23H2, 24H2, 25H2, 26H1), Windows Server 2016, 2019, 2022, and 2025 across multiple architectures. Exploitation requires valid user credentials and network access to SMB services. Microsoft has released fixes for all affected platforms.

What this means
What could happen
An authenticated attacker on the network could read sensitive information from memory in Windows SMB Client, potentially exposing credentials, configuration data, or other confidential details stored on affected systems.
Who's at risk
Windows Server 2016, 2019, 2022, and 2025 systems; Windows 10 (versions 1607, 1809, 21H2, 22H2) and Windows 11 (versions 23H2, 24H2, 25H2, 26H1) on x64, 32-bit, and ARM64 systems. This affects any environment using SMB file sharing, including utilities relying on Windows file sharing for configuration backups, SCADA workstations, or engineering systems connected to production networks.
How it could be exploited
An attacker with valid network credentials connects to an affected Windows system using SMB and sends a specially crafted request to the SMB Client service. The out-of-bounds memory read allows the attacker to retrieve sensitive data from system memory without direct command execution.
Prerequisites
  • Network access to SMB ports (137-139, 445)
  • Valid user credentials or domain membership
  • Target system running affected Windows version with SMB Client enabled
Remotely exploitableRequires valid credentialsLow exploit probability (EPSS 0.9%)Information disclosure only (no code execution)
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 10.0.17763.9245
Windows 10 Version 1809 for x64-based SystemsAll versionsBuild 10.0.17763.9245
Windows Server 2019All versionsBuild 10.0.17763.9245
Windows Server 2019 (Server Core installation)All versionsBuild 10.0.17763.9245
Windows Server 2022All versionsBuild 10.0.20348.5622
Remediation & Mitigation
0/3
Do now
0/1
WORKAROUNDRestrict SMB access (ports 137-139, 445) from untrusted networks using firewall rules
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HOTFIXApply Windows security update for 2026-September to all affected systems
Long-term hardening
0/1
HARDENINGDisable SMB v1 protocol if not required for legacy system compatibility
View full vendor advisory
API: /api/v1/advisories/cb90cb9c-30f5-4640-a0c4-38ed1711017a

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Windows SMB Client Information Disclosure Vulnerability | CVSS 5.7 - OTPulse