CVE-2026-35539 PUBLISHED

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

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS Score: 6.1

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

CVSS 3.1

Product Status

Vendor	Roundcube
Product	Webmail
Versions	Default: unaffected affected from 0 to 1.5.14 (excl.) 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/1b30edf5369668c92fe91dae3d52e477c808aa4f
https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
https://github.com/roundcube/roundcubemail/commit/10a6d1fa8acac85c727b0a6ae4a6642bfa27bea1
https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
https://github.com/roundcube/roundcubemail/commit/d742954ccbcdee7020f8f2e7c49ce0fca5a0efab

Problem Types

CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') CWE