All vulnerabilities
CVE-2024-27443

Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

Synacor Zimbra Collaboration Suite (ZCS)Applications & CMS
Open in ThreatlineRecord JSON
CVSS
6.1Medium
ExploitationExploited in the wildAdded to KEV 19 May 2025CISA KEV
Exploit odds (EPSS)24.6%Chance of exploitation activity in the next 30 days, higher than 97% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Federal deadline9 Jun 2025Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. CISA KEV

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

  1. 12 Aug 2024, 00:00 UTCPublishedCVE List
  2. 19 May 2025Added to CISA KEVCISA KEV

Public exploit code and templates 1

  • Scanner templateZimbra Collaboration - Cross-Site Scripting (XSS)Nuclei

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

Zimbra Collaboration contains a cross-site scripting (XSS) vulnerability in the CalendarInvite feature of the Zimbra webmail classic user interface. An attacker can exploit this vulnerability via an email message containing a crafted calendar header, leading to the execution of arbitrary JavaScript code.

Text from CVE List

Affected versions 1

  • n/aaffected: n/aCVE List

References 6