CVE-2024-42009: Roundcube Webmail

What is CVE-2024-42009?

RoundCube Webmail contains a cross-site scripting vulnerability. This vulnerability could allow 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.

CVSSawaiting NVD

Exploitation In the wild In CISA KEV

EPSS83% · P100

Triage statusActive Exploit

ActionPatch immediately

Timeline

2025-06-09Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2025-06-30CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

RoundCube Webmail Cross-Site Scripting Vulnerability

Added to KEV2025-06-09

Federal patch deadline2025-06-30

Known ransomware useUnknown

Affected product

Roundcube Webmail

Remediation Steps

Identify all Roundcube instances in your environment
Apply the latest Roundcube security patch
Review access logs for indicators of exploitation
Reset credentials for accounts accessed through vulnerable Roundcube instances
Monitor for lateral movement following potential compromise

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 1 of July 2026 (July 6 – 12)

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🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.