CVE-2026-74998
published 2026-08-17CVE-2026-74998: 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…
PriorityP337high7.2CVSS 3.1
AVNACLPRNUINSCCLILAN
EPSS
0.44%
37.0th percentile
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.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| roundcube | webmail | >= 1.6.0 < 1.6.18 | 1.6.18 |
| roundcube | webmail | >= 1.7.0 < 1.7.3 | 1.7.3 |
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing [fedora-all]
bugzilla·2026-08-24·CVSS 7.2
CVE-2026-74998 [HIGH] CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing [fedora-all]
CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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.
Bugzilla
CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing [epel-all]
bugzilla·2026-08-24·CVSS 7.2
CVE-2026-74998 [HIGH] CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing [epel-all]
CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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.
Bugzilla
CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing
bugzilla·2026-08-17·CVSS 7.2
CVE-2026-74998 [HIGH] CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing
CVE-2026-74998 roundcubemail: information disclosure or XSS via MIME sniffing
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.
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
2026-08-17
Published