This security update resolves a vulnerability in Microsoft Office that could allow remote code execution if a user opens a specially crafted Office file. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2017-11826.
Note To apply this security update, you must have the release version of Service Pack 1 for Microsoft Office Web Apps Server 2013 installed on the computer.
Improvements and fixes
This security update fixes the following issue:
When you open some PDF files that have certain image encoding in Word Online, the images may be displayed black.
How to get and install the update
Method 1: Microsoft Update Catalog
To get the stand-alone package for this update, go to the Microsoft Update Catalog website.
Method 2: Microsoft Download Center
You can get the stand-alone update package through the Microsoft Download Center. Follow the installation instructions on the download page to install the update.
Security update deployment information
For deployment information about this update, see security update deployment information: October 10, 2017.
Security update replacement information
This security update replaces previously released security update KB 3213562.
File hash information
Package Hash SHA 1
Package Hash SHA 2
For the list of files that cumulative update 4011231 contains, download the file information for update 4011231.
How to get help and support for this security update
Help for installing updates: Windows Update FAQ
Security solutions for IT professionals: Security Support and Troubleshooting
Help for protecting your Windows-based computer from viruses and malware: Microsoft Secure