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Microsoft Releases October 2026 Security Updates

Scheduled security updates for Microsoft products address 1,413 vulnerabilities, including 3 zero-day vulnerabilities

Threat ID:
CC-4867
Threat Severity:
Medium
Published:
14 October 2026 4:34 PM
Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Scheduled security updates for Microsoft products address 1,413 vulnerabilities, including 3 zero-day vulnerabilities

Affected platforms

The following platforms are known to be affected:

Microsoft Windows Server

.NET Framework

The following platforms are also known to be affected:

Multiple other Microsoft platforms. Please see Microsoft's October 2026 Security Updates guide for full details.

Threat details

Three zero-day vulnerabilities identified

Microsoft states that exploitation of CVE-2026-96951 has been detected. The US Cybersecurity and Infrastructure Security Agency (CISA) has added this vulnerability to the Known Exploited Vulnerabilities (KEV) Catalog.

Two other vulnerabilities, CVE-2026-108398 and CVE-2026-92707, have been reported as publicly disclosed. 

NHS England National CSOC assess that future exploitation is highly likely.

Introduction

Microsoft has released security updates to address 1,413 vulnerabilities in Microsoft products, including the 3 zero-day vulnerabilities highlighted below.

  • CVE-2026-96951 - 'Windows Shell Security Feature Bypass' vulnerability - CVSSv3 score of 8.8.
  • CVE-2026-108398 - '.NET Framework Security Feature Bypass' vulnerability - CVSSv3 score of 8.8.
  • CVE-2026-92707 - 'MessagePack-CSharp Denial of Service' vulnerability - CVSSv3 score of 5.3.

Windows 11, version 24H2 Home and Pro, and Windows 10 Enterprise LTSB 2016 are no longer supported

As of 14 October 2026, Microsoft’s support for Windows 11, version 24H2 Home and Pro, and Windows 10 Enterprise LTSB 2016 has come to an end, therefore these products are now unsupported by Microsoft. Organisations are encouraged to switch to a supported version.

Remediation advice

Affected organisations are encouraged to review Microsoft's October 2026 Security Updates and apply the relevant updates as soon as possible.

Last edited: 14 October 2026 4:45 pm