Zimbra
Hackers breached over 270 Zimbra servers in ongoing attacks
Threat actors have already compromised over 270 Zimbra instances in remote code execution attacks targeting a high-severity Zimbra Collaboration Suite (ZCS) vulnerability. The ZCS email and collaboration suite is used by hundreds of millions of people and organizations, including thousands of businesses and hundreds of government agencies worldwide. Synacor patched the security flaw (tracked as CVE-2026-73570), […]
CISA orders urgent patching of actively exploited Zimbra flaw
The Cybersecurity and Infrastructure Security Agency (CISA) has ordered U.S. government agencies to patch an actively exploited vulnerability in Zimbra Collaboration Suite (ZCS) within three days. The Zimbra security team patched the security flaw (tracked as CVE-2026-73570) in version 10.1.20, released on July 20. Successful exploitation allows unauthenticated attackers to gain remote code execution by exploiting a […]
Critical Zimbra RCE flaw now actively exploited in attacks
CERT Polska, the Polish Computer Emergency Response Team (CERT), warned that attackers have begun exploiting a critical vulnerability in Zimbra Collaboration Suite (ZCS). ZCS is a popular email and collaboration software suite used by hundreds of millions of people and organizations worldwide, including thousands of businesses and hundreds of government agencies. The Zimbra security team released […]
Russian hackers exploit Zimbra zero-click flaw for email theft
CISA is warning that the Russian state-sponsored hacking group Laundry Bear, also known as Void Blizzard, is targeting organizations using Zimbra Collaboration email servers by combining phishing attacks with the exploitation of a now-patched Zimbra vulnerability. According to CISA, Laundry Bear has targeted and compromised users in organizations associated with the Defense Industrial Base (DIB), […]
Zimbra urges customers to patch critical web client XSS flaw
The Zimbra security team urged customers to patch a critical vulnerability affecting the Classic Web Client used to access the Zimbra Collaboration suite. Zimbra is a very popular email and collaboration software suite used by hundreds of millions of people, including thousands of businesses and hundreds of government agencies worldwide. Also known as the Classic […]
Over 10,000 Zimbra servers vulnerable to ongoing XSS attacks
Over 10,000 Zimbra Collaboration Suite (ZCS) instances exposed online are vulnerable to ongoing attacks exploiting a cross-site scripting (XSS) security flaw, according to nonprofit security organization Shadowserver. Zimbra is a popular email and collaboration software suite used by hundreds of millions of people worldwide, including hundreds of government agencies and thousands of businesses. The vulnerability (tracked as CVE-2025-48700) […]
Russian hackers exploit Zimbra flaw in Ukrainian govt attacks
Hackers part of APT28, a state-backed threat group linked to Russia’s military intelligence service (GRU), are exploiting a Zimbra Collaboration Suite (ZCS) vulnerability in attacks targeting Ukrainian government entities. This high-severity security flaw (tracked as CVE-2025-66376 and patched in early November) stems from a stored cross-site scripting (XSS) that unauthenticated attackers can exploit to gain remote code execution (RCE) […]
CISA orders feds to patch Zimbra XSS flaw exploited in attacks
CISA has ordered U.S. government agencies to secure their servers against an actively exploited vulnerability in the Zimbra Collaboration Suite (ZCS). Zimbra is a very popular email and collaboration software suite used by hundreds of millions of people worldwide, including thousands of businesses and hundreds of government agencies. Tracked as CVE-2025-66376 and patched in early November, this high-severity security […]
Critical Zimbra RCE flaw exploited to backdoor servers using emails
Hackers are actively exploiting a recently disclosed RCE vulnerability in Zimbra email servers that can be triggered simply by sending specially crafted emails to the SMTP server. The Zimbra remote code execution flaw is tracked as CVE-2024-45519 and exists in Zimbra’s postjournal service, which is used to parse incoming emails over SMTP. Attackers can exploit the […]