Retired Microsoft Products and the New Risks to Your Cybersecurity

The decisive date is – according to current information – 13 October 2026. From this day on, support will end for several widely used Microsoft products that are still actively used by many SMEs.

Particularly relevant for small and medium-sized businesses:

• Office 2021 & Office LTSC 2021
  The popular perpetual licenses (non-subscription versions) will no longer receive security updates from this date onward.
• Windows Server 2012 / 2012 R2
  The final paid Extended Security Updates (ESU) will also expire. After that, the rule is simple: no patches, no support.
• Exchange & SharePoint Server (ältere On-Premise-Versionen)
  Many installations will lose their security safety net – especially critical for systems accessible from the internet.

From this point on, these systems are officially considered outdated, regardless of whether they still “work” technically.

Data protection and IT security start with keeping software up to date. Any system without security updates is an open door – and those are exactly the doors attackers are looking for.

Ransomware as the Biggest Threat

Cybercriminals often deliberately wait until official support has ended. From that moment on, known but previously undisclosed vulnerabilities are actively exploited.

For any organization, even a single unpatched Outlook or Exchange system can be enough to:

• introduce malware into the network
• encrypt entire file servers
• shut down business operations for days or even weeks

The Underestimated Risk of “Data Liability”

Outdated server systems such as SQL, SharePoint, or Exchange servers are prime targets for data exfiltration. Since no security updates are provided, the detection risk for attackers decreases – while the attack surface for the company grows to its maximum.

The result:

A security incident becomes not only more likely, but also far more problematic from a legal perspective.

In 2026, IT security is no longer a purely technical issue – it is a matter for top management.

GDPR and the “State of the Art”

Article 32 of the GDPR requires companies to implement appropriate technical and organizational measures. Using software without security updates clearly contradicts the recognized “state of the art”.

If an incident occurs, companies may face:

• mandatory reporting of data breaches (72-hour deadline)
• fines
• significant reputational damage

In addition, audits or inquiries by authorities become much harder to handle if known risks were ignored, making it difficult to meet the accountability requirement under Article 5(2) GDPR.

Cyber Insurance

Many cyber insurance policies include clauses that limit or completely exclude coverage if:

• outdated software is used
• security updates were negligently neglected

In a worst-case scenario, this can mean: damage yes – reimbursement no.

E-Invoicing Obligations & Regulatory Side Effects

New legal requirements for digital invoicing and standardized formats may be incompatible with outdated Office or server systems. The result is not only security issues, but also operational disruptions.

A structured transition significantly reduces risks and costs.

Key steps:

1. Inventory
   Document all versions of Office, Windows Server, and connected systems currently in use.
2. Define a migration path
   • Microsoft 365: High security standards, automatic updates, no fixed end-of-support date
   • Office LTSC / on-premises: Only suitable for clearly justified special cases (e.g. isolated systems)
3. Check hardware
   Not every existing infrastructure meets the requirements of modern operating systems (e.g. Windows 11).

Plan the budget early

Licensing, migration, and training costs should be firmly included in the 2026 budget – not treated as emergency expenses.

The Microsoft support end in 2026 marks the final end of the “install and forget” mentality. Cybersecurity is no longer a one-time project, but an ongoing process.

Conclusion:

The era of grace periods is over. Those who plan now not only protect their data, but also avoid stress, downtime, and unnecessary costs. Those who wait will migrate later under time pressure – and that usually comes at a high price.

Can I simply continue using Office 2021 after October 2026?

Technically yes – but in practice it is highly risky. Without security updates, every newly discovered vulnerability becomes a permanent entry point for malware.

Is there a support extension for Office 2021?

For standard perpetual licenses (Home/Business), Microsoft generally does not offer paid support extensions. Switching to a current version is effectively unavoidable.

What is the safest option for SMEs?

From a security perspective, Microsoft 365 is the most robust solution: automatic updates, continuous development, and no fixed end-of-support date that suddenly turns into a risk.