Description
Roundcube Webmail 1.6.x between 1.6.14 and 1.6.16,and 1.7.x before 1.7.1 has Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. The issue stems from an insufficient fix for CVE-2026-35540.
References5
- github.com/roundcube/roundcubemail/commit/ab96c88bfd888866ec5e0…
- github.com/roundcube/roundcubemail/commit/cb3fc9041e91640ba9ba4…
- github.com/roundcube/roundcubemail/releases/tag/1.6.16
- github.com/roundcube/roundcubemail/releases/tag/1.7.1
- roundcube.net/news/2026/05/24/security-updates-1.6.16-and-1.7.1
Metrics
- CVSS 3.1
-
7.2
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 19 · as of 14 November 2026
- CWE
- CWE-918
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.