Microsoft has released security updates to address vulnerabilities in its software products, including a fix for the actively exploited zero-day vulnerability CVE-2025-62221.

These updates apply to, but are not limited to:

• Windows Server: 2016,2019, 2022,2025.

• Microsoft Exchange Server: 2016,2019 and Subscription Edition (SE)

• Microsoft Office: 2016, 2019,2021, 2024.

• Microsoft 365 Apps for Enterprise, and Microsoft Office LTSC 2021,2024.

Security Risks

The identified vulnerabilities could allow authenticated attackers to gain remote access, execute malicious code with elevated privileges, and compromise system integrity and security.

For the full list of security patches released by Microsoft, please refer to the  Microsoft Security Update Guide and apply the necessary updates.

 Recommended Actions

The National Cyber Security Authority (NCSA) recommends users and administrators:

1. Apply the latest security patches as soon as possible to prevent unauthorized control over unpatched systems.

2. Upgrade immediately to the latest supported version of installed Microsoft software to continue receiving technical support and security patches.

The following Microsoft software products reached their end-of-life and need to be upgraded immediately:

• Windows Vista, XP, 8, and 7

• Windows Server 2003, 2003 RE, 2008, 2008 RE, 2008 SP2, 2012, and 2012 R2

• Exchange Server 2003, 2007, 2010, 2013

• Microsoft SQL Server 2005, 2008, 2012, 2014, and Microsoft Office 2013.

3. Before any updating task, ensure you have a current, tested backup of your data.

For further information and support, please contact the National Cyber Security Authority (NCSA) by emailing rwcsirt@ncsa.gov.rw or calling us on 9009.

References

• Microsoft December 2025 Security Release Notes

• https://techcommunity.microsoft.com