Microsoft has released the May 2026 Patch Tuesday security updates addressing more than 120 vulnerabilities, including 17 Critical (14 remote code execution, 2 elevation of privilege, and 1 information disclosure), which could lead to system compromise.

These updates apply to, but are not limited to:

• Windows 11

• Microsoft SQL Server 2022, 2025

• Microsoft Office 2021, 2024

• Microsoft Edge

Security Risks

The identified vulnerabilities could potentially be exploited by attackers to run malicious code, gain elevated privileges, access sensitive information, or disrupt system operations, potentially leading to full compromise of affected systems.

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 soon:

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

• Exchange Server 2003, 2007, 2010, 2013, 2016, 2019, and Windows Vista, XP, 8, and 7, 10.

• Microsoft SQL Server 2005, 2008, 2012, 2014, and MS Office 2013, 2016 and 2019.

Additionally, scheduled for end-of-life in 2026; Upgrade recommended before end of support:

• Microsoft SQL Server 2016: July 14, 2026 and Microsoft Office 2021: October 13, 2026

For more information, including other products reaching end-of-support in 2026, see Microsoft’s official documentation.

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 May 2026 Security Release Notes

• Microsoft May 2026 Patch Tuesday fixes 120 flaws, no zero-days

• Microsoft Ending Support in 2026