Last release of the year — modest in volume, meaningful in impact.
December 2025 delivered a smaller-than-average release, weighted towards Windows kernel and Office issues. The challenge is operational: limited maintenance windows around the holiday period.
- Risk theme: Windows kernel EoP
- Risk theme: Office font parsing RCE
- Risk theme: Print spooler vulnerability
- Risk theme: Edge / WebView2 flaw
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 kernel elevation of privilege
Another in a long line of kernel EoP issues. Routinely chained by malware after an initial foothold.
Office font parsing RCE
A crafted font embedded in a document could trigger code execution. Higher impact than it sounds — fonts are loaded automatically.
Print spooler vulnerability
The print spooler returns once again as an attack surface. Disable where not needed; patch immediately where it is.
Edge / WebView2 flaw
Affects embedded browser components used by many line-of-business applications.
Where the risk lives.
- — Windows 10, 11 and Server
- — Microsoft Office and Microsoft 365 Apps
- — Print services
- — Applications using WebView2 (incl. Teams, third-party LOB)
What to watch for when rolling out.
- Print spooler restart can cause queued jobs to drop — communicate before deployment.
- WebView2 update required a restart of any application using it (Teams, Outlook, etc.).
- Tidies up the year-end attack surface — a good baseline going into the holiday freeze.
- Lower volume means realistic testing within compressed change windows.
- Holiday change freezes leave fewer windows to deploy and validate.
- Reduced support staffing increases the risk if something regresses.
How experienced teams roll these out without drama.
- Deploy to a pilot before the freeze, then schedule the wider rollout for early January.
- Disable Print Spooler on servers that do not need it — single most effective long-term mitigation.
- Restart WebView2-dependent applications as part of the rollout to avoid stale processes.
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.
Get next month's breakdown before you've finished your coffee.
The same practitioner summary you just read — CVE counts, exploited vulnerabilities and rollout guidance — delivered the morning after each Patch Tuesday release.
Always verify against the official Microsoft Security Update Guide and your own asset inventory before deployment.