Cross-site Scripting (XSS) Affecting roundcube package, versions <1.4.15+dfsg.1-1+deb11u11
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-DEBIAN11-ROUNDCUBE-18869288
- published18 Aug 2026
- disclosed17 Aug 2026
Introduced: 17 Aug 2026
CVE-2026-74998 (opens in a new tab)How to fix?
Upgrade Debian:11 roundcube to version 1.4.15+dfsg.1-1+deb11u11 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream roundcube package and not the roundcube package as distributed by Debian.
See How to fix? for Debian:11 relevant fixed versions and status.
In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, responses from the CSS (Cascading Style Sheets) proxy were not validated, which may result in information disclosure or XSS (cross-site scripting) via MIME sniffing.
References
- https://security-tracker.debian.org/tracker/CVE-2026-74998
- https://github.com/roundcube/roundcubemail/commit/62d33c8a0dc3fd0dd03984220dc9709e8e0de43b
- https://github.com/roundcube/roundcubemail/commit/a2334990c02f7cb77b1a8d6fa97fcd9e1b5cd1fb
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.18
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.3
- https://roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3