CVE-2024-42009: RoundCube Webmail Cross-Site Scripting Vulnerability
Affects Roundcube WebmailSource CISA KEV
Exploited in the wild · KEV due 30 Jun 2025 · public detection template (Nuclei) · 82% EPSS : apply the vendor's fix or mitigations to Roundcube Webmail now.
Data as of 10/24/2026, 22:16:00 UTC
- Exploitation
Actively exploited – in CISA KEV since 06/09/2025
- KEV deadline
- 06/30/2025 US federal agencies must patch by this date; a sensible deadline for everyone else.
- EPSS
- 82.8% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Public exploits
- a Nuclei detection templatePublic attack or detection tooling exists; see Public exploits below.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:NWhat to do
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public exploits and detection
Nuclei detection templates
Public tooling indexed from Metasploit Framework, Exploit-DB and ProjectDiscovery nuclei-templates. Its existence raises the odds of exploitation; it does not confirm attacks.
Description
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.
Weaknesses
- CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.