CVE-2020-13965

CVE-2020-13965 is a medium-severity vulnerability in Roundcube Webmail with a CVSS 3.x base score of 6.1. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2024-06-26). The underlying weakness is classified as CWE-79.

Key facts

• Severity: Medium (CVSS 3.x base score 6.1)
• CVSS v2: 4.3
• EPSS exploit prediction: 77% (99th percentile)
• Actively exploited: Yes — listed in CISA KEV (added 2024-06-26)
• EU (EUVD) id: EUVD-2020-6139
• EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2024-06-26)
• Weakness: CWE-79
• Affected product: Roundcube Webmail
• Published: 2020-06-09
• Last modified: 2026-06-17

Description

An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5. There is XSS via a malicious XML attachment because text/xml is among the allowed types for a preview.

Frequently asked questions

What is CVE-2020-13965?

An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5. There is XSS via a malicious XML attachment because text/xml is among the allowed types for a preview.

How severe is CVE-2020-13965?

CVE-2020-13965 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-13965 being actively exploited?

Yes. CVE-2020-13965 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-06-26, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2020-13965?

CVE-2020-13965 primarily affects Roundcube Webmail. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-13965?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2020-13965 have an EU (EUVD) identifier?

Yes. CVE-2020-13965 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-6139. It is also flagged as exploited in the EUVD (since 2024-06-26).

When was CVE-2020-13965 published?

CVE-2020-13965 was published on 2020-06-09 and last updated on 2026-06-17.

References

• https://github.com/DrunkenShells/Disclosures/tree/master/CVE-2020-13965-Cross%20Site-Scripting%20via%20Malicious%20XML%20Attachment-Roundcube
• https://github.com/roundcube/roundcubemail/commit/884eb611627ef2bd5a2e20e02009ebb1eceecdc3
• https://github.com/roundcube/roundcubemail/compare/1.4.4...1.4.5
• https://github.com/roundcube/roundcubemail/releases/tag/1.3.12
• https://github.com/roundcube/roundcubemail/releases/tag/1.4.5
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DLESQ4LPJGMSWHQ4TBRTVQRDG7IXAZCW/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ODPJXBHZ32QSP4MYT2OBCALYXSUJ47SK/
• https://roundcube.net/news/2020/06/02/security-updates-1.4.5-and-1.3.12
• https://www.debian.org/security/2020/dsa-4700
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-13965

Affected products (5)

• cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*

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