CVE-2026-35544
Publication date 6 April 2026
Last updated 6 April 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| roundcube | 25.10 questing |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.3 · Medium
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | Low |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-35544
- https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14
- https://nullcathedral.com/posts/2026-03-18-roundcube-round-two-three-more-sanitizer-bypasses/#css-position-fixed-important
- https://github.com/roundcube/roundcubemail/commit/099009b9c8e1d3c636fb9a5af72f7c2596018662
- https://github.com/roundcube/roundcubemail/commit/226811a1c974271dbedca72672923abaff8191c0
- https://github.com/roundcube/roundcubemail/commit/57dec0c127b98e0c8e3b9c26c80049b9c4bcaea7
- https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
- https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5