Vulnerability Details CVE-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 information disclosure or XSS (cross-site scripting) via MIME sniffing.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 18.8%
CVSS Severity
CVSS v3 Score 7.2
References
- 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
Products affected by CVE-2026-74998
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cpe:2.3:a:roundcube:webmail:*
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cpe:2.3:a:roundcube:webmail:1.6.0
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cpe:2.3:a:roundcube:webmail:1.6.1
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cpe:2.3:a:roundcube:webmail:1.6.10
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cpe:2.3:a:roundcube:webmail:1.6.11
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cpe:2.3:a:roundcube:webmail:1.6.12
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cpe:2.3:a:roundcube:webmail:1.6.13
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cpe:2.3:a:roundcube:webmail:1.6.14
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cpe:2.3:a:roundcube:webmail:1.6.2
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cpe:2.3:a:roundcube:webmail:1.6.3
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cpe:2.3:a:roundcube:webmail:1.6.4
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cpe:2.3:a:roundcube:webmail:1.6.5
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cpe:2.3:a:roundcube:webmail:1.6.6
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cpe:2.3:a:roundcube:webmail:1.6.7
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cpe:2.3:a:roundcube:webmail:1.6.8
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cpe:2.3:a:roundcube:webmail:1.6.9