---
id: CVE-2026-114731
title: >-
  Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an
  uncontrolled resource consumption vulnerability in the CSS proxy (the
  utils/modcss action)
summary: >-
  Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an
  uncontrolled resource consumption vulnerability in the CSS proxy (the
  utils/modcss action). The fetched stylesheet was read into memory in full,
  with no size limit …
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-770
vendor: Roundcube
product: Webmail
affected:
  - Webmail >= 1.6.0 < 1.6.20
  - Webmail >= 1.7.0 < 1.7.5
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T02:12:34.577Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114731'
references:
  - url: 'https://bugs.debian.org/1151279'
  - url: >-
      https://github.com/roundcube/roundcubemail/commit/2c9f6da692fa37cad2aaf85d5b127b583d22b264
  - url: 'https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5'
  - url: 'https://github.com/roundcube/roundcubemail/releases/tag/1.7.5'
  - url: 'https://github.com/roundcube/roundcubemail/releases/tag/1.6.20'
  - url: >-
      https://github.com/roundcube/roundcubemail/commit/99a5bdd05b01f45493cc0da4c96968eac7668126
tags:
  - cve.org
ingestedAt: '2026-10-22T03:25:15.662Z'
---

## Overview

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an uncontrolled resource consumption vulnerability in the CSS proxy (the utils/modcss action). The fetched stylesheet was read into memory in full, with no size limit and no read timeout, so a stylesheet URL referencing an attacker-controlled host could be used to exhaust server memory. Upstream fixed this in the commit “Add a size limit to the CSS proxy content processing”, which caps the response at 5 MB, reads it as a stream and applies a read timeout.

## Affected

- `Webmail >= 1.6.0 < 1.6.20`
- `Webmail >= 1.7.0 < 1.7.5`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.