Zimbra Collaboration Suite 10.0/10.1 Exchange Web Service xml external entity reference

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Zimbra Collaboration Suite 10.0/10.1. The affected element is an unknown function of the component Exchange Web Service. Performing a manipulation results in xml external entity reference. This vulnerability was named CVE-2026-33371. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as critical, was found in Zimbra Collaboration Suite 10.0/10.1. This affects an unknown code of the component Exchange Web Service. The manipulation with an unknown input leads to a xml external entity reference vulnerability. CWE is classifying the issue as 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. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at wiki.zimbra.com. This vulnerability is uniquely identified as CVE-2026-33371 since 03/19/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/26/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-13696). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.3

VulDB Base Score: 6.3
VulDB Temp Score: 6.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 4.3
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Xml external entity reference
CWE: CWE-611 / CWE-610
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/19/2026 CVE reserved
03/20/2026 +1 days Advisory disclosed
03/20/2026 +0 days VulDB entry created
03/26/2026 +6 days VulDB entry last update

Sourcesinfo

Advisory: wiki.zimbra.com
Status: Confirmed

CVE: CVE-2026-33371 (🔒)
GCVE (CVE): GCVE-0-2026-33371
GCVE (VulDB): GCVE-100-352083
EUVD: 🔒

Entryinfo

Created: 03/20/2026 15:47
Updated: 03/26/2026 18:09
Changes: 03/20/2026 15:47 (54), 03/20/2026 17:39 (1), 03/26/2026 18:09 (12)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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