---
id: "CVE-2023-5631"
kind: "vulnerability"
aliases: ["CVE-2023-5631"]
title: "Roundcube before 1.4.15, 1.5.x before 1.5.5, and 1.6.x before 1.6.4 allows stored XSS via an HTML e-mail message\u2026"
severity: "medium"
cvss: 6.1
epss: null
exploited: true
status: "open"
category: "other"
products: [{"name": "roundcube webmail", "fixed": ["1.4.15"], "affected": "< 1.4.15", "ecosystem": "vendor"}, {"name": "roundcube webmail", "fixed": ["1.5.5"], "affected": ">= 1.5.0, < 1.5.5", "ecosystem": "vendor"}, {"name": "roundcube webmail", "fixed": ["1.6.4"], "affected": ">= 1.6.0, < 1.6.4", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 10.0", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 11.0", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 12.0", "ecosystem": "vendor"}, {"name": "fedoraproject fedora", "fixed": [], "affected": "= 39", "ecosystem": "vendor"}, {"name": "Roundcube Webmail", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "other", "roundcube", "self-hosted", "webmail"]
not_affected_if: ["unknown"]
published_at: "2023-10-18T15:15:08+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-2023-5631", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-5631", "first_seen_at": "2026-10-23T22:29:04+00:00"}]
---

# Roundcube before 1.4.15, 1.5.x before 1.5.5, and 1.6.x before 1.6.4 allows stored XSS via an HTML e-mail message…

Roundcube Webmail, a web-based email client, has a persistent cross-site scripting flaw that lets a remote attacker run malicious JavaScript in a user's browser session. CISA lists it as actively exploited in the wild.

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

## Affected

- vendor:roundcube webmail affected < 1.4.15 fixed 1.4.15
- vendor:roundcube webmail affected >= 1.5.0, < 1.5.5 fixed 1.5.5
- vendor:roundcube webmail affected >= 1.6.0, < 1.6.4 fixed 1.6.4
- vendor:debian linux affected = 10.0 fixed ?
- vendor:debian linux affected = 11.0 fixed ?
- vendor:debian linux affected = 12.0 fixed ?
- vendor:fedoraproject fedora affected = 39 fixed ?
- vendor:Roundcube Webmail affected ? fixed ?

## Fix

Apply the vendor mitigation per Roundcube instructions, or discontinue use of the product if mitigations are unavailable (per CISA required action). Specific fixed version: unknown

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-5631
- 2026-10-23T22:29:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-5631

## From the sources

Roundcube Webmail contains a persistent cross-site scripting (XSS) vulnerability that allows a remote attacker to run malicious JavaScript code.

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_