CVE-2026-35540 PUBLISHED

Assigner: mitre
Reserved: 03.04.2026 Published: 03.04.2026 Updated: 03.04.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
CVSS Score: 5.4

Attack Vector	Network	Scope	Changed
Attack Complexity	High	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Roundcube
Product	Webmail
Versions	Default: unaffected affected from 1.6.0 to 1.6.14 (excl.)

References

https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14
https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66c765648942
https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76d619caa6870

Problem Types

CWE-669 Incorrect Resource Transfer Between Spheres CWE