CVE-2026-20856: CWE-20: Improper Input Validation in Microsoft Windows 10 Version 1607
Improper input validation in Windows Server Update Service allows an unauthorized attacker to execute code over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-20856) arises from improper input validation in the Windows Server Update Service component of Windows 10 Version 1607 (build 10.0.14393.0). An attacker can exploit this flaw remotely to execute arbitrary code without privileges or user interaction, potentially leading to full system compromise. The CVSS 3.1 vector indicates network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. Microsoft has released a patch to remediate this vulnerability.
Potential Impact
Successful exploitation allows remote code execution by an unauthenticated attacker, resulting in complete compromise of the affected system's confidentiality, integrity, and availability. This could lead to unauthorized control over the system and disruption of services.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Windows 10 Version 1607 (build 10.0.14393.0) to remediate the issue. No additional mitigation guidance is provided or required beyond applying the patch.
CVE-2026-20856: CWE-20: Improper Input Validation in Microsoft Windows 10 Version 1607
Description
Improper input validation in Windows Server Update Service allows an unauthorized attacker to execute code over a network.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-20856) arises from improper input validation in the Windows Server Update Service component of Windows 10 Version 1607 (build 10.0.14393.0). An attacker can exploit this flaw remotely to execute arbitrary code without privileges or user interaction, potentially leading to full system compromise. The CVSS 3.1 vector indicates network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. Microsoft has released a patch to remediate this vulnerability.
Potential Impact
Successful exploitation allows remote code execution by an unauthenticated attacker, resulting in complete compromise of the affected system's confidentiality, integrity, and availability. This could lead to unauthorized control over the system and disruption of services.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Windows 10 Version 1607 (build 10.0.14393.0) to remediate the issue. No additional mitigation guidance is provided or required beyond applying the patch.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-03T05:54:20.380Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69668ae0a60475309f9ae102
Added to database: 1/13/2026, 6:11:44 PM
Last enriched: 4/3/2026, 12:46:01 PM
Last updated: 5/9/2026, 12:26:20 AM
Views: 118
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.