Microsoft Office 2016 Pro Plus 16.0.4266.1001 V... Jun 2026

Microsoft Office 2016 Professional Plus: Exploring Version 16.0.4266.1001

Microsoft’s own Security Update Guide shows that only builds with version numbers >= 16.0.4575.1000 have protection against the most severe remote execution attacks. Build 4266.1001 is essentially defenseless against these.

Get-ItemProperty HKLM:\Software\Microsoft\Office\16.0\Common\ProductVersion

Officially unsupported, but it may run in compatibility mode. Security risks are much higher, however. Microsoft Office 2016 Pro Plus 16.0.4266.1001 V...

Yes. Office 2016’s “16.0” core version maps to marketing version “1609” for early builds. “1609” indicates September 2016, which matches the timeframe.

| CVE ID | Severity | Description | |--------|----------|-------------| | CVE-2017-0199 | Critical | Malicious RTF file execution | | CVE-2017-11882 | Critical | Equation Editor memory corruption | | CVE-2019-0801 | Critical | Remote code execution via PowerPoint | | CVE-2021-40444 | High | MSHTML browser engine exploit |

This particular build is notable for being: Security risks are much higher, however

That looks like a very specific version number for a Microsoft Office installation, but the way you've phrased it suggests you might be looking for something more than just technical specs. Since that string is often associated with software activation , or specific build history

Key milestones in Office 2016’s version history include:

Instead of using an obsolete, possibly unauthorized build: “1609” indicates September 2016

However, because this is build 4266.1001, later enhancements like the are missing.

Microsoft Office 2016 Professional Plus version is the original Release to Manufacturing (RTM) build, representing the initial standalone release of the suite. This version introduced a range of productivity and collaboration features that evolved the Office experience from previous editions. Core Included Applications