---
id: "CVE-2017-0143"
kind: "vulnerability"
aliases: ["CVE-2017-0143"]
title: "Microsoft Windows: Microsoft Windows Server Message Block (SMBv1) Remote Code Execution Vulnerability"
severity: "critical"
cvss: 9.3
epss: 0.93307
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Microsoft Windows", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "ransomware", "self-hosted", "smbv1", "windows"]
not_affected_if: ["no-windows-hosts", "smbv1-disabled"]
published_at: "2017-03-17T00:59:03+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T21:57:34+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2017-0143", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2017-0143", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2017-0143", "first_seen_at": "2026-10-23T21:57:34+00:00"}]
---

# Microsoft Windows: Microsoft Windows Server Message Block (SMBv1) Remote Code Execution Vulnerability

Microsoft Windows SMBv1 (Server Message Block 1.0) has a remote code execution flaw, tracked as CVE-2017-0143 and known as the EternalBlue exploit path. An unauthenticated attacker who can reach the SMB port can run code on the Windows machine.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft Windows affected ? fixed ?

## Fix

Apply the Microsoft security update for CVE-2017-0143 per vendor instructions (CISA required action).

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2017-0143
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2017-0143
- 2026-10-23T21:57:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2017-0143

## From the sources

The SMBv1 server in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows Server 2012 Gold and R2; Windows RT 8.1; and Windows 10 Gold, 1511, and 1607; and Windows Server 2016 allows remote attackers to execute arbitrary code via crafted packets, aka "Windows SMB Remote Code Execution Vulnerability." This vulnerability is different from those described in CVE-2017-0144, CVE-2017-0145, CVE-2017-0146, and CVE-2017-0148.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_