Russian hackers exploit unpatched Zimbra servers to steal emails

Russian state-backed hacker group Laundry Bear has been breaking into government and commercial networks for at least a year by exploiting a vulnerability in the Zimbra Collaboration Suite (ZCS) webmail platform. Laundry Bear (also known as Void Blizzard, CL-STA-1114, and TA488) has been running the campaign since July 2025, according to a joint advisory from the NSA, FBI, CISA, and cybersecurity agencies from the Netherlands, UK, Australia, Canada, and a dozen other countries.