---
id: "CVE-2026-114717"
kind: "vulnerability"
aliases: ["CVE-2026-114717"]
title: "Roundcube Webmail: forwarded-as-attachment subject lets mail headers be injected"
severity: "medium"
cvss: 4.0
epss: 0.00298
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["mail", "package", "roundcube", "self-hosted"]
not_affected_if: ["patched-version"]
published_at: "2026-10-22T02:16:59+00:00"
first_seen_at: "2026-10-23T21:57:30+00:00"
updated_at: "2026-10-25T04:41:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-114717", "first_seen_at": "2026-10-23T21:57:30+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-114717", "first_seen_at": "2026-10-24T07:15:52+00:00"}]
---

# Roundcube Webmail: forwarded-as-attachment subject lets mail headers be injected

Roundcube builds the attachment name for a forwarded message directly from that message's subject, without stripping line breaks. A received email whose subject contains CRLF sequences can therefore inject extra MIME part headers into the outgoing message.

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

## How to check

- Check the Roundcube version: `1.6.x` below `1.6.20` or `1.7.x` below `1.7.5` is affected.
- Confirm the installed release from the Roundcube package or the `program/include/iniset.php` version constant.

## Fix

- Upgrade Roundcube to `1.6.20` or later on the 1.6 line, or to `1.7.5` or later on the 1.7 line.
- Until patched, unknown whether a configuration change mitigates it; the sources do not say.

## Timeline

- 2026-10-23T21:57:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-114717
- 2026-10-24T07:15:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-114717

## From the sources

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a mail header injection vulnerability when a message is forwarded as an attachment. The subject of the forwarded message was used verbatim to generate the attachment name, so a received message whose subject contains CRLF sequences could inject arbitrary MIME part headers into the outgoing message. Upstream fixed this in the commit “Fix mail header injection via subject of a message forwarded as attachment”, which collapses whitespace in the generated name.

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