---
id: "CVE-2020-13965"
kind: "vulnerability"
aliases: ["CVE-2020-13965"]
title: "An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5"
severity: "medium"
cvss: 6.3
epss: null
exploited: true
status: "open"
category: "package"
products: [{"name": "roundcube webmail", "fixed": ["1.3.12"], "affected": "< 1.3.12", "ecosystem": "vendor"}, {"name": "roundcube webmail", "fixed": ["1.4.5"], "affected": ">= 1.4.0, < 1.4.5", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 9.0", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 10.0", "ecosystem": "vendor"}, {"name": "fedoraproject fedora", "fixed": [], "affected": "= 31", "ecosystem": "vendor"}, {"name": "fedoraproject fedora", "fixed": [], "affected": "= 32", "ecosystem": "vendor"}, {"name": "Roundcube Webmail", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["email", "exploited", "package", "roundcube", "self-hosted"]
not_affected_if: ["unknown"]
published_at: "2020-06-09T03:15:11+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-13965", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-13965", "first_seen_at": "2026-10-23T22:29:05+00:00"}]
---

# An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5

Roundcube Webmail has a cross-site scripting flaw triggered by a malicious XML attachment. An attacker who gets a user to open such a message can run script in the victim's webmail session.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:roundcube webmail affected < 1.3.12 fixed 1.3.12
- vendor:roundcube webmail affected >= 1.4.0, < 1.4.5 fixed 1.4.5
- vendor:debian linux affected = 9.0 fixed ?
- vendor:debian linux affected = 10.0 fixed ?
- vendor:fedoraproject fedora affected = 31 fixed ?
- vendor:fedoraproject fedora affected = 32 fixed ?
- vendor:Roundcube Webmail affected ? fixed ?

## Fix

Apply the vendor mitigation or upgrade Roundcube to a fixed release; the sources do not name the fixed version.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-13965
- 2026-10-23T22:29:05+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2020-13965

## From the sources

Roundcube Webmail contains a cross-site scripting (XSS) vulnerability that allows a remote attacker to manipulate data via a malicious XML attachment.

CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_