Description
In Roundcube Webmail 1.6.x before 1.6.16 and 1.7.x before 1.7.1, the remote image blocking feature can be bypassed via a crafted CSS var() value in an e-mail message, which may lead to information disclosure or access-control bypass.
References5
- github.com/roundcube/roundcubemail/commit/59cca80908a61e662c5f8…
- github.com/roundcube/roundcubemail/commit/852350486b88b35b8544e…
- 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
-
6.5
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 35 · as of 14 November 2026
- CWE
- CWE-669
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.