Prepare for Windows Update certificate rotation in 2027

🚨 The Signal: Windows Update certificates expire in 2027. Devices must have updated certificates to continue receiving security updates, critical for maintaining system integrity and protection against vulnerabilities.

The Impact

Unsupported or unpatched Windows devices will lose update access, creating significant security vulnerabilities.

• Unsupported Windows devices will stop receiving security updates.
• Unpatched in-support devices will lose access to Windows Update.
• Organisations will face increased attack surface from unpatched systems.
• Compliance posture will degrade due to unmanaged vulnerabilities.

The Action

1. Identify all Windows devices running unsupported versions.
2. Upgrade unsupported Windows devices to a supported version.
3. Ensure all in-support Windows 11/Server 2022 devices are current with updates.
4. For Windows 11 24H2/Server 2025, install the September 2025 security update or later.

Domain: Other · Impact: high · Workload: Other · Essential Eight: Patch Operating Systems · ISM: ISM-1407, ISM-1501, ISM-1621, ISM-1622, ISM-1623, ISM-1654, ISM-1655, ISM-1694, ISM-1695, ISM-1696, ISM-1701, ISM-1702, ISM-1877, ISM-1889, ISM-1902