XXE in Zimbra Collaboration

CVE-2020-35123

In Zimbra Collaboration Suite Network Edition versions < 9.0.0 P10 and 8.8.15 P17, there exists an XXE vulnerability in the saml consumer store extension, which is vulnerable to XXE attacks. This has been fixed in Zimbra Collaboration Suite Network edition 9.0.0 Patch 10 and 8.8.15 Patch 17.

Vulnerability class: XXE (XML External Entity)

Published 2020-12-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS 0.015, 74.8th percentile (scored 2026-11-12); unchanged over 30 days. About EPSS.

Affected products

Zimbra Collaboration — versions 8.8.15, 9.0.0

Weakness classification (CWE)

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

References

wiki.zimbra.com/wiki/Security_Center (Product)
wiki.zimbra.com/wiki/Zimbra_Security_Advisories (Vendor Advisory)
wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P10 (Third Party Advisory, Vendor Advisory)
wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P17 (Release Notes, Vendor Advisory)