Risk Letters

Exploited vulnerability

CVE-2025-48700

TLP:CLEAR

Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability

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.

Facts

  • Vendor: Synacor
  • Product: Zimbra Collaboration Suite (ZCS)
  • CVSS: 6.1
  • EPSS (probability of exploitation within 30 days): 1.7 %
  • On CISA's Known Exploited Vulnerabilities list since: 20 April 2026
  • First known exploitation: 20 April 2026
  • CISA's deadline for US federal agencies: 23 April 2026
  • Weakness: CWE-79
  • First seen by Risk Letters: 20 April 2026

Members see which Nordic sectors the flaw hits, and what to do about it.

Get the full brief

Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD