Microsoft has released its October 2026 security updates addressing 1,411 vulnerabilities, including one actively exploited zero-day, CVE-2026-96951, and two publicly disclosed zero-days, CVE-2026-108398 and CVE-2026-92707. The updates also address 70 critical‑severity vulnerabilities, which may allow unauthorized access or elevated control of affected systems.

These updates apply to, but are not limited to:

• Windows OS: 11.

• Windows Server: 2022, 2025

• Microsoft Office: 2024

• Exchange Server Subscription Edition(SE)

• Microsoft 365 and Microsoft Edge

Security Risks

Successful exploitation of these vulnerabilities could enable attackers to gain unauthorized access, execute malicious code, escalate privileges, or gain full control of affected systems, resulting in compromise of sensitive data and disruption of critical operations.

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, 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, 2016 and MS Office 2013, 2016, and 2019.

• Microsoft Office LTSC 2021.

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 October 2026 Security Release Notes

• Microsoft October 2026 Patch Tuesday fixes 1,411 flaws, 3 zero-days

• Released: October 2026 Exchange Server Security Updates