Nowadays, emails are an indispensable part of our daily lives - both at work and at home. But what if these seemingly harmless messages suddenly become a threat to the security of your PC? A new vulnerability in Microsoft Outlook allows hackers to install malware without you even having to do anything. The danger is already lurking the moment you read an email. But don't worry - we'll show you how you can protect yourself from this threat.
This is how dangerous the Outlook security vulnerability is
The security vulnerability with the identifier CVE-2025-21298 in the Outlook program poses a serious threat. In the past, hackers often had to hope that the user would click on a dangerous link or download a file. But this new vulnerability makes it much easier: simply opening or previewing a compromised email is enough to execute malware on your system. This means that you can be infected just by reading an email - without doing anything.
Why is this vulnerability so dangerous? Because it allows hackers to steal your data, manipulate your software or even take over your system completely. Attackers can use this method to access your emails undetected and leave no immediately visible traces. And the best (or rather worst) thing for the attackers: they don't need any interaction from you to cause damage.
What can you do to protect yourself?
The German Federal Office for Information Security (BSI) has already warned of this threat and recommends a quick response. Fortunately, Microsoft has already released an update that fixes this vulnerability. It is therefore advisable to update your Windows version to the latest version so that you are automatically protected by the security update.
In the event that the update is not installed automatically, you should carry it out manually. To do this, you simply need to search for the corresponding KB number - this is the security update identifier. In Windows 11 24H2 the number is KB5050009, for earlier versions of Windows 11 it is KB5050021, and for Windows 10 there is KB5049981. You can easily install the update using the Windows Update function.
An eye-opener for digital security
The recent discovery of this vulnerability in Outlook shows how important it is to regularly update your own devices and take security guidelines seriously. Nowadays, it is no longer enough to be careful when surfing the internet - dangerous traps also lurk in email communication.
Unfortunately, security vulnerabilities in software are nothing new. But the fact that this malware is executed without any user interaction is a particularly worrying signal. We live in an age where we constantly have to weigh up convenience against risk. Microsoft's patch is a step in the right direction - but how many users have already ignored it? True protection does not start with an update, but with the responsibility of each individual to regularly check whether their own system is secure. When it comes to IT security, negligence is almost a crime.
