CVE-2020-13965Known exploitationPublic exploitNetwork attack vector

Cross-site scripting via XML preview

Published Jun 9, 2020 · Updated Oct 21, 2025

Cross-site scripting in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5 allows remote authenticated users to execute script in a browser via a malicious XML attachment. The mail preview code treated text/xml as a browser-preview MIME type without a safe XML parser, allowing attacker-controlled markup to execute when a recipient opened the attachment. Exploitation requires a user to access the message and open the attachment; impact is script execution in the Roundcube origin, including data access or actions available to that session.

CVSS severity6.1
Medium
EPSS probability76.60%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5 allows remote authenticated users to execute script in a browser via a malicious XML attachment. The mail preview code treated text/xml as a browser-preview MIME type without a safe XML parser, allowing attacker-controlled markup to execute when a recipient opened the attachment. Exploitation requires a user to access the message and open the attachment; impact is script execution in the Roundcube origin, including data access or actions available to that session.

The record

CVE
CVE-2020-13965
Published
Jun 9, 2020
Updated
Oct 21, 2025
Vendor
Roundcube
Product
Roundcube Webmail
Classifications
CWE-80, CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2020CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 2024Exploitation reportedCVE-2020-13965 in CISA Known Exploited Vulnerabilities Catalog
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.3.12
  2. Affected versionversion=1.4.0 <1.4.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Roundcube · Roundcube Webmailversion=0 <1.3.12; version=1.4.0 <1.4.5

Published CVSS scores

6.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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