CVE-2026-74998
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.2epss 0.3%
exploitation probability
0.3%top 75% of all CVEs
observed exploitation
nono source reports it
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 · WebmailReferences
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