CVE-2025-48700

Cross-site Scripting in Synacor Zimbra Collaboration Suite (ZCS). CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 20 April 2026.

Product
Synacor Zimbra Collaboration Suite (ZCS)
Added to CISA's catalog
Federal fix-by date
Ransomware
No known use in ransomware campaigns

CISA’s description.

Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that could allow attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information.
  • CVE-2026-73570 Zimbra Collaboration Suite (ZCS) OS Command Injection, added
  • CVE-2025-66376 Cross-Site Scripting, added
  • CVE-2020-7796 (ZCS) Server-Side Request Forgery, added
  • CVE-2025-68645 PHP Remote File Inclusion, added

Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.