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

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2025-06-09. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2024-08-05T00:00:00.000Z
• Last modified: 2025-10-21T22:55:48.964Z
• Added to CISA KEV: 2025-06-09
• BOD 22-01 due: 2025-06-30

09References

• github.com — https://github.com/roundcube/roundcubemail/releases
• sonarsource.com — https://sonarsource.com/blog/government-emails-at-risk-critical-cross-site-scrip…
• github.com — https://github.com/roundcube/roundcubemail/releases/tag/1.5.8
• github.com — https://github.com/roundcube/roundcubemail/releases/tag/1.6.8
• roundcube.net — https://roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8