Vulnerability in Email Security: What Does This Mean for Your Business?

A serious vulnerability has recently been discovered in Exim, a widely used system for sending and receiving email. This vulnerability, technically named 'Dead.Letter' (CVE-2026-45185), can have severe consequences: attackers could potentially gain control over systems that are not properly updated. The impact is high, with a severity score of 9.8 out of 10, indicating this is a critical issue.

Exim often runs on servers that handle email traffic for companies. The vulnerability lies in how certain versions of the software handle incoming emails, particularly via GnuTLS. This can lead to 'memory corruption,' an error where data in the computer's memory is processed incorrectly. In the worst-case scenario, this can give attackers the opportunity to execute their own malicious code on your systems.

What does this mean for SMEs?

For SMEs, it is important to know if your email infrastructure uses Exim. Although most companies outsource their email services to providers (such as Microsoft 365 or Google Workspace), there are also SMEs that manage their own mail servers. If you have your own mail server, it is crucial to keep the software up to date. Check directly with your IT administrator or supplier to see if your systems are protected against this vulnerability. Timely updating is the most effective way to protect yourself against the risks of cyberattacks.

Do you have questions about this or would you like advice on securing your IT systems? Assist2go is happy to help you with clear explanations and practical solutions. Contact us for a secure digital working environment.