Start of the cycle — a balanced release with two notable Critical CVEs.
June 2025 kicked off our twelve-month archive with a balanced release including two Critical vulnerabilities in Windows networking and a SharePoint Server RCE worth prioritising.
- Risk theme: Windows networking Critical RCE
- Risk theme: SharePoint Server RCE
- Risk theme: Office click-to-run flaw
- Risk theme: Defender update
The issues that move the needle this month.
We have focused on the categories with realistic exploitation paths for UK SMEs and regulated firms. Always cross-check with Microsoft's Security Update Guide and your own asset inventory before deployment.
Windows networking Critical RCE
Pre-authentication remote code execution on exposed Windows hosts. Top priority for any internet-reachable server.
SharePoint Server RCE
Authenticated attackers could execute code on the SharePoint server itself. Relevant for firms with internal portals.
Office click-to-run flaw
Realistic phishing vector. Patches deploy automatically for most click-to-run installations once the update channel updates.
Defender update
Engine and platform update with new detection signatures.
Where the risk lives.
- — Windows 10, 11 and Server
- — SharePoint Server (Subscription Edition)
- — Microsoft Office and Microsoft 365 Apps
- — Microsoft Defender for Endpoint
What to watch for when rolling out.
- SharePoint update required Configuration Wizard run.
- Defender platform update temporarily affected scan scheduling for a small subset of devices.
- Closes a pre-auth RCE — meaningfully reduces attack surface.
- Establishes a strong patching baseline going into the summer.
- SharePoint patching is operationally heavy.
- Networking fixes require server reboots, often in maintenance windows.
How experienced teams roll these out without drama.
- Run the SharePoint Configuration Wizard on every server in the farm.
- Audit which Windows hosts are actually internet-reachable — surprises here drive most incidents.
- Confirm Defender platform version across the estate post-deployment.
Advice, guidance, or full remediation — your call.
Whether you want a second pair of eyes on this month's release or you would rather hand the entire patching cycle to us, Secure Chain Technology Group can support at any level of involvement.
- Advisory: a prioritised briefing mapped to your estate and risk appetite, with recommended rollout rings.
- Guided deployment: we work alongside your IT team — test plans, rollback procedures and change-management evidence.
- Fully managed remediation: we deploy, validate and report on every patch through our Vulnerability Management-as-a-Service (VMaaS) and Patch Management services.
- Compliance evidence: reporting aligned to Cyber Essentials Plus, ISO 27001 and DSPT requirements.
Always verify against the official Microsoft Security Update Guide and your own asset inventory before deployment.