CVE-2019-0541 Microsoft MSHTML Remote Code Execution Vulnerability
Microsoft MSHTML engine contains an improper input validation vulnerability that allows for remote code execution vulnerability.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 3 Nov 2021.
- Rated High severity (CVSS 8.8, scored by CISA).
- It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
A remote code execution vulnerability exists in the way that the MSHTML engine inproperly validates input, aka "MSHTML Engine Remote Code Execution Vulnerability." This affects Microsoft Office, Microsoft Office Word Viewer, Internet Explorer 9, Internet Explorer 11, Microsoft Excel Viewer, Internet Explorer 10, Office 365 ProPlus.
Affected Versions
| Product | Versions |
|---|---|
| Microsoft Microsoft Office | 2010 Service Pack 2 (32-bit editions) 2010 Service Pack 2 (64-bit editions) 2013 RT Service Pack 1 2013 Service Pack 1 (32-bit editions) 2013 Service Pack 1 (64-bit editions) 2016 (32-bit edition) |
| Microsoft Microsoft Office Word Viewer | Microsoft Office Word Viewer |
| Microsoft Internet Explorer 9 | Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Server 2008 for x64-based Systems Service Pack 2 |
| Microsoft Internet Explorer 11 | Windows 10 for 32-bit Systems Windows 10 for x64-based Systems Windows 10 Version 1607 for 32-bit Systems Windows 10 Version 1607 for x64-based Systems Windows 10 Version 1703 for 32-bit Systems Windows 10 Version 1703 for x64-based Systems |
| Microsoft Microsoft Excel Viewer | 2007 Service Pack 3 |
| Microsoft Internet Explorer 10 | Windows Server 2012 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Microsoft MSHTML. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
- 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
Vendor Advisories
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
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