CVE-2026-74998: high-severity vulnerability in Roundcube Webmail
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.2epss 0.3%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Affected products
Roundcube · WebmailRelated CVEs — Roundcube Webmail
In the same product, most dangerous first.
References
https://github.com/roundcube/roundcubemail/commit/62d33c8a0dc3fd0dd03984220dc9709e8e0de43bhttps://github.com/roundcube/roundcubemail/commit/a2334990c02f7cb77b1a8d6fa97fcd9e1b5cd1fbhttps://github.com/roundcube/roundcubemail/releases/tag/1.6.18https://github.com/roundcube/roundcubemail/releases/tag/1.7.3https://roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3