CVE-2026-33371Network attack vector

Authenticated local-file disclosure via external entities

Published Mar 20, 2026 · Updated Mar 20, 2026

XXE in the EWS SOAP interface in Zimbra Collaboration 10.0 and 10.1 allows remote authenticated users to read sensitive local files. An XML parser processes crafted SOAP input with external entity resolution enabled, causing attacker-supplied entities to retrieve server files. A valid Zimbra account and network access to EWS are required; the documented consequence is local-file disclosure without write access or service interruption.

CVSS severity4.3
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in the EWS SOAP interface in Zimbra Collaboration 10.0 and 10.1 allows remote authenticated users to read sensitive local files. An XML parser processes crafted SOAP input with external entity resolution enabled, causing attacker-supplied entities to retrieve server files. A valid Zimbra account and network access to EWS are required; the documented consequence is local-file disclosure without write access or service interruption.

The record

CVE
CVE-2026-33371
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-611, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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