CVE-2026-33371
XXE Vulnerability in Zimbra EWS Allows Sensitive File Disclosure
Publication date: 2026-03-20
Last updated on: 2026-04-01
Assigner: MITRE
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| synacor | zimbra_collaboration_suite | From 10.0.0 (inc) to 10.1.16 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-611 | The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is an XML External Entity (XXE) issue found in Zimbra Collaboration (ZCS) versions 10.0 and 10.1. It exists in the Zimbra Exchange Web Services (EWS) SOAP interface because the system improperly handles XML input. Specifically, an authenticated attacker can submit specially crafted XML data that is processed by an XML parser with external entity resolution enabled.
This improper handling allows the attacker to exploit the XML parser to access and disclose sensitive local files from the server.
How can this vulnerability impact me? :
The impact of this vulnerability is that an authenticated attacker could gain unauthorized access to sensitive local files on the server running Zimbra Collaboration. This could lead to the disclosure of confidential information stored on the server.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know