https://www.bleepingcomputer.com/news/security/barracuda-warns-of-email-gateways-breached-via-zero-day-flaw/

Barracuda, a company known for its email and network security solutions, warned customers today that some of their Email Security Gateway (ESG) appliances were breached last week by targeting a now-patched zero-day vulnerability.

On Friday, May 19, a vulnerability was discovered in the email attachment scanning module. The issue was addressed by applying two security patches on May 20 and 21.