CVE-2026-35539

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.

Score

CVSS 3.1 6.1 Medium

Status

Analyzed - cve@mitre.org

Published

2026-04-03

Last modified

2026-04-03

Weaknesses

CWE-79

Affected products

• Webmail (Roundcube)

References

• https://github.com/roundcube/roundcubemail/commit/10a6d1fa8acac85c727b0a6ae4a6642bfa27bea1
• https://github.com/roundcube/roundcubemail/commit/1b30edf5369668c92fe91dae3d52e477c808aa4f
• https://github.com/roundcube/roundcubemail/commit/d742954ccbcdee7020f8f2e7c49ce0fca5a0efab
• https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
• 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