CVE-2026-33371 XML external entity in n/a
An authenticated attacker can exploit an XXE vulnerability in Zimbra's EWS SOAP interface to disclose sensitive local files from the server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33371?
CVE-2026-33371 is a medium-severity vulnerability in Synacor Zimbra Collaboration Suite, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-611
Which versions are affected by CVE-2026-33371?
It affects 1 product.
Products include Synacor Zimbra Collaboration Suite.
How do I fix CVE-2026-33371?
No fix has been published for CVE-2026-33371 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-33371 being exploited?
There is no known exploitation of CVE-2026-33371 in the wild and no public exploit code.
Other vulnerabilities in Synacor Zimbra Collaboration Suite
- CVE-2024-45519 Synacor Zimbra Collaboration Suite (ZCS) Command Execution
- CVE-2022-41352 Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload
- CVE-2022-37042 Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass
- CVE-2022-27924 Synacor Zimbra Collaboration Suite (ZCS) Command Injection
- CVE-2020-7796 Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery
Sources
Also known as GHSA-mc6f-xmmw-r6pv.