CVE-2024-42009: RoundCube Webmail Cross-Site Scripting Vulnerability

Critical severity, CVSS 9.3. Actively exploited: in CISA KEV since 2025-06-09. EPSS: 82.9% chance of exploitation in the next 30 days.

A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7 allows a remote attacker to steal and send emails of a victim via a crafted e-mail message that abuses a Desanitization issue in message_body() in program/actions/mail/show.php.

Affected products

• Roundcube Webmail: before 1.5.8 (fixed in 1.5.8); from 1.6.0, before 1.6.8 (fixed in 1.6.8)

Published 2024-08-05. Last modified 2026-06-17.