Windows DHCP Server Information Disclosure Vulnerability
MonitorCVSS 5.9CVE-2026-69803Sep 8, 2026
Microsoft
IT in OT - Windows Server and Active Directory are widely deployed in OT environments
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityHigh
User InteractionNone needed
Summary
An out-of-bounds read vulnerability in Windows DHCP Server allows an unauthorized attacker to read memory and disclose sensitive information over the network. The vulnerability does not allow code execution or denial of service—only unauthorized information disclosure. The DHCP Server role is present on Windows Server systems running DHCP service and may be present on Windows 10/11 systems if explicitly configured.
What this means
What could happen
An attacker could read sensitive data from DHCP Server memory without authentication, potentially exposing configuration details, credentials, or other network information stored by the service.
Who's at risk
Organizations running Windows DHCP Server on Windows Server 2016, 2019, 2022, or 2025 should prioritize this. Windows 10 systems with DHCP Server explicitly enabled are also affected but less common. This matters to network infrastructure teams managing DHCP services for any facility (water authority, electric utility, manufacturing, etc.).
How it could be exploited
An attacker with network access to the DHCP Server (typically UDP port 67 or 68, or TCP 67) can send a specially crafted DHCP request that triggers an out-of-bounds read, allowing them to retrieve memory contents from the DHCP Server process without providing valid credentials.
Prerequisites
- Network access to DHCP Server ports (UDP 67/68)
- DHCP Server service must be running
- No authentication required
remotely exploitableno authentication requireddefault credentials not required but service may listen by default on Server editionsaffects network infrastructure
Exploitability
Unlikely to be exploited — EPSS score 0.8%
Affected products (12)
12 with fix
ProductAffected VersionsFix Status
Remediation & Mitigation
0/3
Do now
0/1WORKAROUNDRestrict network access to DHCP Server ports (UDP 67/68) to only authorized DHCP clients and relay agents using firewall rules
Schedule — requires maintenance window
0/1Patching may require device reboot — plan for process interruption
HOTFIXApply the 2026-Sep (September 2026) Windows security update to all Windows Server and Windows 10 systems running DHCP Server role
Long-term hardening
0/1HARDENINGDisable DHCP Server service on Windows 10 systems if not needed for operations
CVEs (1)
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