What’s Vulnerable › Vulnerabilities

CVE-2026-33371

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-20 · updated 2026-06-17
• Weakness: CWE-611

Description

An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. An XML External Entity (XXE) vulnerability exists in the Zimbra Exchange Web Services (EWS) SOAP interface due to improper handling of XML input. An authenticated attacker can submit crafted XML data that is processed by an XML parser with external entity resolution enabled. Successful exploitation may allow disclosure of sensitive local files from the server.

Affected products

• Zimbra Collaboration: from 10.0.0 before 10.1.16 — fixed in 10.1.16

How to fix

Upgrade to a fixed version: Zimbra Collaboration 10.1.16. Check the vendor advisory for mitigations.

References

• https://wiki.zimbra.com/wiki/Security_Center
• https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.16#Security_Fixes
• https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy
• https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

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