What is CVE-2019-11318?

CVE-2019-11318 is a medium-severity vulnerability in Synacor Zimbra Collaboration Server, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-01-27.

How severe is CVE-2019-11318?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Synacor Zimbra Collaboration Server

CVE-2019-11318

Zimbra Collaboration before 8.8.12 Patch 1 has persistent XSS.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-01-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.011 (64.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 64.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Synacor Zimbra Collaboration Server

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

wiki.zimbra.com/wiki/Zimbra_Security_Advisories (Vendor Advisory)
wiki.zimbra.com/wiki/Security_Center (Patch, Vendor Advisory)
bugzilla.zimbra.com/show_bug.cgi (Permissions Required, Issue Tracking, Vendor Advisory)
wiki.zimbra.com/wiki/Zimbra_Releases/8.8.12/P1 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2019-11318?: CVE-2019-11318 is a medium-severity vulnerability in Synacor Zimbra Collaboration Server, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-01-27.
How severe is CVE-2019-11318?: Medium severity. CVSS v3 base score is 5.4 out of 10.