Known exploited vulnerability

CVE-2019-9670

Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference

Past due Added Federal deadline

What is affected

Vendor Synacor
Product Zimbra Collaboration Suite (ZCS)
Weakness CWE-611

The vulnerability

Synacor Zimbra Collaboration Suite (ZCS) contains an improper restriction of XML external entity (XXE) vulnerability in the mailboxd component.

Required action

Apply updates per vendor instructions.

US federal civilian agencies were required to act by 10 July 2022 under BOD 22-01. The deadline is a compliance date, not a measure of severity — it says nothing about how dangerous the flaw is to anyone else.

Where this comes from

Every field on this page is taken from the CISA Known Exploited Vulnerabilities catalog, last synced 12 Nov 2026, 00:29. Nothing here is our own assessment. For the technical scoring, see the NVD record below.

NVD record ↗ CVE.org record ↗

More from Synacor

CVE-2026-73570

Synacor Zimbra Collaboration Suite (ZCS)

Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability

Past due · 21 Aug 2026 CVE-2025-48700

Synacor Zimbra Collaboration Suite (ZCS)

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

Past due · 20 Apr 2026 CVE-2025-66376

Synacor Zimbra Collaboration Suite (ZCS)

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

Past due · 18 Mar 2026 CVE-2020-7796

Synacor Zimbra Collaboration Suite

Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability

Past due · 17 Feb 2026