Incorrect Resource Transfer Between Spheres Affecting roundcube/roundcubemail package, versions <1.5.14>=1.6-beta, <1.6.14>=1.7-beta, <1.7-rc5
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PHP-ROUNDCUBEROUNDCUBEMAIL-15911838
- published6 Apr 2026
- disclosed3 Apr 2026
- creditUnknown
Introduced: 3 Apr 2026
NewCVE-2026-35544 (opens in a new tab)How to fix?
Upgrade roundcube/roundcubemail to version 1.5.14, 1.6.14, 1.7-rc5 or higher.
Overview
Affected versions of this package are vulnerable to Incorrect Resource Transfer Between Spheres in the CSS sanitization process for HTML email messages. An attacker can inject malicious CSS by crafting specially formatted HTML emails that exploit the lack of proper sanitization, potentially bypassing fixed-position mitigations using the !important directive.