CVE-2016-9920: Roundcube Webmail

High severity, CVSS 7.5. EPSS: 5.6% chance of exploitation in the next 30 days.

steps/mail/sendmail.inc in Roundcube before 1.1.7 and 1.2.x before 1.2.3, when no SMTP server is configured and the sendmail program is enabled, does not properly restrict the use of custom envelope-from addresses on the sendmail command line, which allows remote authenticated users to execute arbitrary code via a modified HTTP request that sends a crafted e-mail message.

Affected products

• Roundcube Webmail: up to and including 1.1.6; version 1.2.0 only; version 1.2.1 only; version 1.2.2 only

Published 2016-12-08. Last modified 2026-06-17.