New Vulnerability in Microsoft Exchange: What Does This Mean for Your Business?

Microsoft has recently announced a new security risk that affects on-premise versions of their Exchange Server software. This is important news, as many Dutch companies use these servers to manage their email. The problem, known by the technical name CVE-2026-42897, is serious and is already actively being exploited by cybercriminals. This means that attacks are already taking place that leverage this flaw.

It is a so-called 'spoofing' vulnerability. Simply put, this means that attackers can impersonate someone else. For example, they can send emails that appear to come from a trusted source, such as a colleague, the boss, or even a known supplier. The goal of this is often to extract sensitive information, such as passwords, or to spread malicious software (viruses). This happens via specially crafted emails that exploit the flaw in the Exchange Server.

What does this specifically mean for SMB companies? If your company uses its own Microsoft Exchange Server (i.e., not the cloud version of Microsoft 365), you are currently at risk. Cybercriminals may try to gain access to your systems or steal sensitive information through this channel. It is crucial to take action quickly. Microsoft releases security updates to fix these types of problems. Ensure that your system administrator installs these updates on your Exchange Server as soon as possible. If you are unsure whether you use an on-premise Exchange Server, or what steps you need to take, please contact your IT partner or Assist2go. We are happy to help you safeguard your digital security.