Quickly update your computer. They are selling this security vulnerability on the dark web in order to gain control of your Windows system without your knowledge.
When hackers steal confidential data or passwords, they use the dark web to sell their loot. In this case, they are selling a previously unknown vulnerability (a zero-day exploit) in Windows Remote Desktop Services. We will explain what this vulnerability is and how to protect yourself from it and avoid the problems that could compromise your security.
This vulnerability, identified as CVE-2026-21533, was first flagged by the Spanish National Institute for Cybersecurity (INCIBE) last February. A zero-day vulnerability is a flaw unknown to the manufacturer or developer, meaning no security updates are initially available, allowing attackers to exploit the system.
It's important to note that Microsoft disclosed this vulnerability last February. Now, a hacker is allegedly selling software to exploit it on the dark web for $220,000. This news was reported in an article published by Cyber Security News on March 8th.
This vulnerability allows an attacker to gain extensive privileges and control over the system. The attacker indicates that those interested in purchasing this exploit need only contact him via private message. This is a serious problem, as it could severely compromise the security of work environments.
As you can see, the price is extremely high. According to experts, this indicates that the software is highly reliable and can target a wide range of outdated systems within the Windows architecture. This also highlights the rapid spread of critical security vulnerabilities worldwide.
This security vulnerability affects a wide range of Microsoft operating systems, including Windows 10, Windows 11, and Windows Server versions, from the 2012 release to the latest 2025 release. Therefore, many computers are vulnerable to this problem.
This vulnerability has a CVSSv3 rating of 7.8, indicating its extreme severity. Immediate action is crucial to address the issue. To do so, the latest available Microsoft security updates should be installed. Experts also recommend that administrators disable Remote Desktop Services (RDS) if not absolutely necessary, restrict access to trusted networks, and implement Endpoint Detection and Response (EDR) solutions.
To check if you have the latest version of Windows installed, go to Start, then Settings, then Windows Update. There you will find information about whether your system is up to date. If an update is available, you can download and install it.
It's essential to check for updates to avoid this type of attack. However, it's advisable to update cautiously and always back up your important data, as previous Windows updates have contained numerous vulnerabilities that can cause computers to restart randomly and even malfunction—a serious problem, especially in work environments. Therefore, create a backup or image of your current operating system in case you need to revert to a previous version.
In short, a program exploiting an unknown Windows vulnerability has been released for sale. It is crucial to ensure you have the latest versions installed to avoid any issues that could compromise your security.