CVE-2016-3235 Microsoft Office OLE DLL Side Loading Vulnerability
Microsoft Office Object Linking & Embedding (OLE) dynamic link library (DLL) contains a side loading vulnerability due to it improperly validating input before loading libraries. Successful exploitation allows for remote code execution.
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 7.8, 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
Microsoft Visio 2007 SP3, Visio 2010 SP2, Visio 2013 SP1, Visio 2016, Visio Viewer 2007 SP3, and Visio Viewer 2010 mishandle library loading, which allows local users to gain privileges via a crafted application, aka "Microsoft Office OLE DLL Side Loading Vulnerability."
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Microsoft Office. 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?
Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2016-3235 and every other exploited flaw on the list.
Sources
- CISA Known Exploited Vulnerabilities catalogue
- NVD: CVE-2016-3235
- CVE record: CVE-2016-3235
- FIRST EPSS
- securify.nl/advisory/SFY20150804/microsoft_visio_multiple_dll_side_loading_vulnerabilities.html
- docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-070
- securityfocus.com/archive/1/538685/100/0/threaded
- securitytracker.com/id/1036093
- packetstormsecurity.com/files/137490/Microsoft-Visio-DLL-Hijacking.html
- seclists.org/fulldisclosure/2016/Jun/32
