ACTIVELY EXPLOITED

CVE-2023-34192: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

Facts
VendorSynacor
ProductZimbra Collaboration Suite (ZCS)
Actively exploitedYes
Added to CISA KEV25 Feb 2025
CISA federal deadline18 Mar 2025
Weakness (CWE)CWE-79

Required action (CISA's text)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Description (NVD)

Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability that allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.

SOURCES

Other Synacor flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.