CVE-2019-9670: Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2022-01-10. EPSS: 100% chance of exploitation in the next 30 days.

mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, as demonstrated by Autodiscover/Autodiscover.xml.

Affected products

• Synacor Zimbra Collaboration Suite: from 8.7.0, before 8.7.11 (fixed in 8.7.11); version 8.7.11 only

Published 2019-05-29. Last modified 2026-06-17.