CVE-2026-35544
Low
No strong exploitation signal.
CVSS base
5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS — probability of exploitation (30 days)
0.5%
40.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-669
Published 2026-04-03 · modified 2026-07-24
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | L | Low |
| Availability | N | None |
Timeline
- 2026-04-03 — Published (NVD)
- 2026-07-24 — Last modified (NVD)
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.
Affected
References
- 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
- https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14