CVE-2026-33371
An XML External Entity (XXE) vulnerability exists in the Zimbra Exchange Web Services (EWS) SOAP interface due to improper handling of XML input.
Does this matter?
Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-611
- Affected
- synacor/zimbra collaboration suite
- Source
- cve@mitre.org
References
- https://wiki.zimbra.com/wiki/Security_CenterRelease Notes, Vendor Advisory
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.16#Security_FixesRelease Notes
- https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_PolicyProduct
- https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.