EUVD-2026-18591
GHSA-xpqh-grpw-4xmg
5.3
CVSS 3.1
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CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Lifecycle Timeline
4
Patch Released
Apr 04, 2026 - 08:30 nvd
Patch available
EUVD ID Assigned
Apr 03, 2026 - 04:30 euvd
EUVD-2026-18591
Analysis Generated
Apr 03, 2026 - 04:30 vuln.today
CVE Published
Apr 03, 2026 - 03:59 nvd
MEDIUM 5.3
Description
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to a fixed-position mitigation bypass via the use of !important.
Analysis
Roundcube Webmail before versions 1.5.14 and 1.6.14 allows unauthenticated remote attackers to bypass CSS-based security mitigations in HTML email rendering by injecting !important declarations, enabling potential integrity attacks such as phishing or UI redressing. The vulnerability stems from insufficient CSS sanitization when processing HTML email messages, with no authentication required and minimal attack complexity.
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Priority Score
27
Low
Medium
High
Critical
KEV: 0
EPSS: +0.0
CVSS: +26
POC: 0
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