CVE-2018-20160

CRITICALNVD 9.89.8—

9.8

ZxChat (aka ZeXtras Chat), as used for zimbra-chat and zimbra-talk in Synacor Zimbra Collaboration Suite 8.7 and 8.8 and in other products, allows XXE attacks, as demonstrated by a crafted XML request to mailboxd.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 82.3%
KEV: Not listed

Published

May 29, 2019

Last Modified

November 21, 2024

References (6)

cve@mitrehttps://bugzilla.zimbra.com/show_bug.cgi?id=109093
cve@mitrehttps://wiki.zimbra.com/wiki/Security_Center
cve@mitrehttps://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.zimbra.com/show_bug.cgi?id=109093
af854a3a-2127-422b-91ae-364da2661108https://wiki.zimbra.com/wiki/Security_Center
af854a3a-2127-422b-91ae-364da2661108https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-611Improper Restriction of XML External Entity Reference (XXE)

Data Freshness Timeline

(refreshed 10× in last 7d / 19× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:14 UTCepss_batch
2026-05-31 00:14 UTCepss_batch
2026-05-29 13:41 UTCepss_batch
2026-05-28 13:42 UTCepss_batch
2026-05-28 13:42 UTCepss_batch
2026-05-27 18:59 UTCEG score recompute
2026-05-27 18:59 UTCGHSA enrichment
2026-05-27 13:38 UTCepss_batch
2026-05-27 13:38 UTCepss_batch
2026-05-27 08:44 UTCOSV refresh
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2018-20160?

CVE-2018-20160 is a critical vulnerability published on May 29, 2019. ZxChat (aka ZeXtras Chat), as used for zimbra-chat and zimbra-talk in Synacor Zimbra Collaboration Suite 8.7 and 8.8 and in other products, allows XXE attacks, as demonstrated by a crafted XML request to mailboxd.

When was CVE-2018-20160 disclosed?

CVE-2018-20160 was first published in the National Vulnerability Database on May 29, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2018-20160 actively exploited?

CVE-2018-20160 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 82.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2018-20160?

CVE-2018-20160 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2018-20160?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-20160, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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CVE-2018-20160

📅 Published

🔄 Last Modified

🔗 References (6)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2018-20160?

🔗 Related CVEs(same CWE)

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Published

Last Modified

References (6)

Frequently asked(5)

Related CVEs(same CWE)