A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain reque

Summary

The vulnerability affects Microsoft Windows systems that use the SMBv3 file-sharing protocol, in both client and server roles. An attacker who can reach an affected system over the network could potentially run arbitrary code on it.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Timeline

1. Mar 12, 2020, 3:48 PM UTCCVE published
2. Mar 14, 2020Public exploit on Exploit-DB

   EDB-48216, EDB-48267, EDB-48537

3. Feb 10, 2022Added to CISA KEV

   CISA has evidence of exploitation in the wild

4. Aug 10, 2022CISA remediation deadline

   Due date for US federal agencies to patch

5. Aug 12, 2026, 3:55 AM UTCCISA SSVC assessment

   Exploitation: active · Automatable: yes · Technical impact: total

6. Oct 1, 2026, 7:56 PM UTCRecord last updated
7. Oct 22, 2026EPSS reached 10%

   FIRST estimates at least a 10% chance of exploitation in the next 30 days

Affected versions

• Microsoft Windows 10 Version 1903 for 32-bit Systems

  Version range not reported

• Microsoft Windows 10 Version 1903 for x64-based Systems

  Version range not reported

• Microsoft Windows 10 Version 1903 for ARM64-based Systems

  Version range not reported

• Microsoft Windows Server, version 1903 (Server Core installation)

  Version range not reported

• Microsoft Windows 10 Version 1909 for 32-bit Systems

  Version range not reported

• Microsoft Windows 10 Version 1909 for x64-based Systems

  Version range not reported

• Microsoft Windows 10 Version 1909 for ARM64-based Systems

  Version range not reported

• Microsoft Windows Server, version 1909 (Server Core installation)

  Version range not reported

References 10