---
id: "CVE-2012-1856"
kind: "vulnerability"
aliases: ["CVE-2012-1856"]
title: "Microsoft Office: Microsoft Office MSCOMCTL.OCX Remote Code Execution Vulnerability"
severity: "critical"
cvss: 9.3
epss: 0.72032
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Microsoft Office", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "microsoft-office", "windows"]
not_affected_if: ["no-office-installed"]
published_at: "2012-08-15T01:55:01+00:00"
first_seen_at: "2026-10-23T19:11:52+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2012-1856", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2012-1856", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2012-1856", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Microsoft Office: Microsoft Office MSCOMCTL.OCX Remote Code Execution Vulnerability

Microsoft Office's MSCOMCTL.OCX Common Controls library has a flaw in the TabStrip ActiveX control that corrupts system state when a crafted document or web page is opened. An attacker who gets a user to open such a file or page can run arbitrary code on that machine.

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

## Affected

- vendor:Microsoft Office affected ? fixed ?

## Fix

Apply the Microsoft updates for Office and Windows that address MSCOMCTL.OCX, per vendor instructions (CISA KEV required action).

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2012-1856
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2012-1856
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2012-1856

## From the sources

The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office 2003 SP3, Office 2003 Web Components SP3, Office 2007 SP2 and SP3, Office 2010 SP1, SQL Server 2000 SP4, SQL Server 2005 SP4, SQL Server 2008 SP2, SP3, R2, R2 SP1, and R2 SP2, Commerce Server 2002 SP4, Commerce Server 2007 SP2, Commerce Server 2009 Gold and R2, Host Integration Server 2004 SP1, Visual FoxPro 8.0 SP1, Visual FoxPro 9.0 SP2, and Visual Basic 6.0 Runtime allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption, aka "MSCOMCTL.OCX RCE Vulnerability."

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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_