Description
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a remote content blocking bypass in the handling of FuncIRI attributes. rcube_washtml detected the CSS url() token with a pattern that enumerated only some of its escaped spellings, so values using other CSS escape sequences, for example \000075rl( or u\72 l(, were not recognized and remote content was loaded from an HTML message without the user's consent. Upstream fixed this in the commit “Fix remote content blocking bypass via CSS escapes in FuncIRI attributes (again)”, which resolves CSS escapes before matching and also inspects the `to`, `from` and `by` attributes.
Affected products
roundcube: webmail
References6
- github.com/roundcube/roundcubemail/commit/2f74267f0e13bed7182b1… Patch
- github.com/roundcube/roundcubemail/commit/ff4fcfdd2952f9d09947c… Patch
- bugs.debian.org/1151279 Third Party AdvisoryMailing List
- github.com/roundcube/roundcubemail/releases/tag/1.6.20 Release Notes
- github.com/roundcube/roundcubemail/releases/tag/1.7.5 Release Notes
- roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5 Issue TrackingRelease Notes
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 32 · as of 8 November 2026
- CWE
- CWE-184
Could this be exploited in your environment?
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