---
id: "CVE-2020-1380"
kind: "vulnerability"
aliases: ["CVE-2020-1380"]
title: "Microsoft Internet Explorer: Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability"
severity: "high"
cvss: 8.8
epss: 0.24188
exploited: true
status: "open"
category: "runtime"
products: [{"name": "Microsoft Internet Explorer", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "internet-explorer", "runtime", "windows"]
not_affected_if: ["no-ie-installed"]
published_at: "2020-08-17T19:15:14+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-2020-1380", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2020-1380", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-1380", "first_seen_at": "2026-10-23T21:57:34+00:00"}]
---

# Microsoft Internet Explorer: Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability

Internet Explorer's scripting engine has a memory corruption bug that lets a web page run code as the current user. It is listed in CISA's Known Exploited Vulnerabilities catalog, meaning attacks have been seen in the wild.

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

## Affected

- vendor:Microsoft Internet Explorer affected ? fixed ?

## How to check

Check whether Internet Explorer is installed and still in use, for example via the Windows optional features list or by running iexplore.exe.

## Fix

Apply the Microsoft security updates for the affected Internet Explorer versions per vendor instructions; remove or disable Internet Explorer where it is no longer needed.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-1380
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2020-1380
- 2026-10-23T21:57:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2020-1380

## From the sources

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability.
The security update addresses the vulnerability by modifying how the scripting engine handles objects in memory.

---

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