ESET researchers have revealed that the Winter Vivern Russian hacking group has exploited a zero-day vulnerability in Roundcube Webmail, targeting various European government entities and think tanks.

ESET Research has been closely tracking the cyberespionage operations of Winter Vivern for more than a year and, during our routine monitoring, we found that the group began exploiting a zero-day XSS ...

Low-profile threat group Winter Vivern has been exploiting a zero-day flaw in Roundcube Webmail servers with a malicious email campaign targeting governmental organizations and a think tank in Europe ...

Hackers are likely starting to exploit CVE-2025-49113, a critical vulnerability in the widely used Roundcube open-source webmail application that allows remote execution. The security issue has been ...