SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2024-42009

RoundCube Webmail Cross-Site Scripting Vulnerability

KEVCRITICAL 9.3EPSS 82.9%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 30 June 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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.

CVSS 3.1
9.3 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
EPSS
82.88% probability · 100th percentile
CISA KEV
Listed 9 June 2025 · due 30 June 2025
Weakness
CWE-79
Affected
roundcube/webmail
Source
cve@mitre.org

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8 ; https://nvd.nist.gov/vuln/detail/CVE-2024-42009

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.