Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Roundcube | Webmail | >= 1.6.0, < 1.6.14 |
Related Weaknesses (CWE)
References
- https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76dPatch
- https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66Patch
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.14Release Notes
- https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5Release Notes
- https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14Vendor Advisory
FAQ
What is CVE-2026-35540?
CVE-2026-35540 is a vulnerability with a CVSS score of 5.4 (MEDIUM). 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 st...
How severe is CVE-2026-35540?
CVE-2026-35540 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-35540?
Check the references section above for vendor advisories and patch information. Affected products include: Roundcube Webmail.