CISA KEV catalog
Confirmed active exploitation.
Listed in CISA's catalog of Known Exploited Vulnerabilities: attackers are using it in real attacks. Patch it with priority.
- Name
- Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference
- Added to catalog
- Remediation due date (US federal)
- Required action
- Apply updates per vendor instructions.
Description
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
References10
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories Vendor Advisory
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories Vendor Advisory
- bugzilla.zimbra.com/show_bug.cgi?id=109129 Broken LinkIssue TrackingPatchThird Party Advisory
- bugzilla.zimbra.com/show_bug.cgi?id=109129 Broken LinkIssue TrackingPatchThird Party Advisory
- packetstormsecurity.com/files/152487/Zimbra-Collaboration-Autod… ExploitThird Party AdvisoryVDB Entry
- isc.sans.edu/forums/diary/CVE20199670+Zimbra+Collaboration+Suit… ExploitThird Party Advisory
- www.exploit-db.com/exploits/46693/ ExploitThird Party AdvisoryVDB Entry
- packetstormsecurity.com/files/152487/Zimbra-Collaboration-Autod… ExploitThird Party AdvisoryVDB Entry
- isc.sans.edu/forums/diary/CVE20199670+Zimbra+Collaboration+Suit… ExploitThird Party Advisory
- www.exploit-db.com/exploits/46693/ ExploitThird Party AdvisoryVDB Entry
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 100% percentile: 100 · as of 10 November 2026
- CWE
- CWE-611
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