Is It On KEV?

Synacor Zimbra Collaboration Suite (ZCS)

YES - ON THE CISA KEV LIST
CVE-2023-34192

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

CISA catalog due date2025-03-18
overdue since 2025-03-18
EPSS exploit probability (next 30 days)77.3% · 100percentile
From CVE publication to KEV listing600 days (2023-07-06 → 2025-02-25)
Remediation window (KEV listing to due date)21 days
Days on the KEV list624 days
Date added to KEV2025-02-25
Known ransomware campaign useUnknown
VendorSynacor
ProductZimbra Collaboration Suite (ZCS)
Weaknesses (CWE)CWE-79

Synacor: 19 entries (1.1% of all KEV entries are from this vendor); 5 added in 2026.

BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.

Your BOD 26-04 window (SSVC tier helper)

Your remediation window ends:

Description

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.

Required action (CISA)

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

Notes

https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories ; https://nvd.nist.gov/vuln/detail/CVE-2023-34192

References

Other KEV entries for this vendor: Synacor

Synacor - Vendors with KEV entries

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