Man-in-the-Middle Security Flaw in Dovecot by Open-Xchange

CVE-2026-33603

What is CVE-2026-33603?

An attacker can exploit a vulnerability in Dovecot by intercepting and manipulating the base64 data exchanged during SCRAM TLS channel binding. This requires the attacker to position themselves between the Dovecot server and the client connection. Successfully executing this attack allows the attacker to eavesdrop on communications, potentially leading to unauthorized access or data leaks. It is crucial to update to the patched version of Dovecot to mitigate this risk, as currently, no public exploits have been reported.

References