CISA Warns of Zimbra, SharePoint Flaw Exploits; Cisco Zero-Day Hit in Ransomware Attacks

The Hacker News

March 19, 2026 at 6:05 AM

Actively Exploited

Ransomware CVE Zero-day Microsoft Cisco Vulnerability

Overview

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has alerted government agencies about two significant security vulnerabilities affecting the Synacor Zimbra Collaboration Suite (ZCS) and Microsoft Office SharePoint. Both flaws, identified as CVE-2025-66376 and another not specified in the article, have been found to be actively exploited by attackers. The CVE-2025-66376 vulnerability has a CVSS score of 7.2, indicating a moderate to high risk. Organizations using these platforms are urged to apply the necessary patches to protect against potential attacks. The exploitation of these vulnerabilities underscores the need for timely updates and vigilance in cybersecurity practices, especially for government entities.

Key Takeaways

Active Exploitation: This vulnerability is being actively exploited by attackers. Immediate action is recommended.
Affected Systems: Synacor Zimbra Collaboration Suite (ZCS), Microsoft Office SharePoint
Action Required: Government agencies are advised to apply patches for the vulnerabilities in Zimbra and SharePoint as soon as possible.
Timeline: Newly disclosed

Original Article Summary

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has urged government agencies to apply patches for two security flaws impacting Synacor Zimbra Collaboration Suite (ZCS) and Microsoft Office SharePoint, stating they have been actively exploited in the wild. The vulnerabilities in question are as follows - CVE-2025-66376 (CVSS score: 7.2) - A stored cross-site scripting

Impact

Synacor Zimbra Collaboration Suite (ZCS), Microsoft Office SharePoint

Exploitation Status

This vulnerability is confirmed to be actively exploited by attackers in real-world attacks. Organizations should prioritize patching or implementing workarounds immediately.

Timeline

Newly disclosed

Remediation

Government agencies are advised to apply patches for the vulnerabilities in Zimbra and SharePoint as soon as possible. Specific patch numbers or versions were not mentioned in the article.

Additional Information

This threat intelligence is aggregated from trusted cybersecurity sources. For the most up-to-date information, technical details, and official vendor guidance, please refer to the original article linked below.

Related Topics: This incident relates to Ransomware, CVE, Zero-day, and 3 more.

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