CVE-2026-35540
Publication date 6 April 2026
Last updated 6 April 2026
Ubuntu priority
Description
An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.
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 |
5.4 · Medium
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Changed |
| Confidentiality | Low |
| Integrity impact | Low |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-35540
- https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14
- https://i0.rs/blog/turning-a-roundcube-link-tag-into-a-zero-day-ssrf-and-data-exfiltration/
- https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76d619caa6870
- https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66c765648942
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
- https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5