Incorrect Resource Transfer Between Spheres Affecting roundcube package, versions <1.6.20+dfsg-0+deb13u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.25% (16th percentile)

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  • Snyk IDSNYK-DEBIAN13-ROUNDCUBE-21431270
  • published22 Oct 2026
  • disclosed22 Oct 2026

Introduced: 22 Oct 2026

NewCVE-2026-114722  (opens in a new tab)
CWE-669  (opens in a new tab)

How to fix?

Upgrade Debian:13 roundcube to version 1.6.20+dfsg-0+deb13u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream roundcube package and not the roundcube package as distributed by Debian. See How to fix? for Debian:13 relevant fixed versions and status.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a CSS scoping bypass in HTML messages. rcube_utils::mod_css_styles() did not treat an at-rule prologue such as @layer a; as a selector boundary, and did not handle selectors beginning with ::, so selectors following an at-rule were left unscoped and applied to the whole Roundcube interface instead of being confined to the message body. This allows an HTML message to restyle application chrome for UI redressing and spoofing. Upstream fixed this in the commit “Fix CSS scoping bypass in HTML messages using at-rules”.