CVE-2026-33368
Reflected XSS in Zimbra Webmail REST Interface Allows Account Hijack
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-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
What immediate steps should I take to mitigate this vulnerability?
I don't know
Can you explain this vulnerability to me?
Zimbra Collaboration Suite (ZCS) versions 10.0 and 10.1 have a reflected cross-site scripting (XSS) vulnerability in their Classic Webmail REST interface (/h/rest). This vulnerability occurs because the application does not properly sanitize user-supplied input. An unauthenticated attacker can craft a URL containing malicious JavaScript code. When a victim user clicks on this URL, the malicious script executes within the context of the Zimbra webmail application.
How can this vulnerability impact me? :
The vulnerability allows an attacker to execute malicious JavaScript code in the context of the victim's Zimbra webmail session. This can enable the attacker to perform actions on behalf of the victim user, potentially leading to unauthorized access to user data, session hijacking, or other malicious activities within the webmail application.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
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How can this vulnerability be detected on my network or system? Can you suggest some commands?
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