CVE-2026-35540

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.

Score

CVSS 3.1 6.5 Medium

Status

Analyzed - cve@mitre.org

Published

2026-04-03

Last modified

2026-04-03

Weaknesses

CWE-669

Affected products

• Webmail (Roundcube)

References

• 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
• https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14