Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2024-42009

Roundcube Webmail Cross-Site Scripting

Roundcube Webmail

Watch CVE-2024-42009 Browse KEV feed
Severity
CVSS 9.3 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
82.9%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2024-42009 is an unauthenticated vulnerability affecting Roundcube Webmail. 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...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Roundcube Webmail.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Roundcube Webmail Cross-Site Scripting

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.

Published
05 Aug 2024
Exploitation Reported
01 Jun 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
Required

Tags

nuclei_scanner php cisa

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 01 Jun 2026

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 11 Feb 2025

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2026-06-01 10:32 UTC
CISA 2026-06-02 14:07 UTC
The Hacker News 2026-07-07 10:20 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2024/CVE-2024-42009.yaml 01 Jun 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.3 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

EPSS

82.9%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE-79

Recent mention · The Hacker News

Suspected China-Aligned Hackers Exploit Roundcube Flaws Against Universities

A suspected China-aligned threat activity cluster has been observed exploiting Roundcube webmail software belonging to physics and engineering departments of U.S. and Canadian universities as part of a new campaign. The activity involves the exploitation of now-patched,...

Read full advisory

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Roundcube Webmail - Cross-Site Scripting

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 10:20 UTC

    KEV confirmed by The Hacker News

    Exploitation attested by an external source

  2. 14:21 UTC

    Public PoC available

    Public proof-of-concept code published

  3. 14:07 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 15:34 UTC

    Nuclei template available

    Scanner coverage available

  5. 10:32 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  6. 00:00 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2024-42009

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2024-42009",
  "confidence": "Confirmed",
  "cvss_score": 9.3,
  "cvss_estimated": false,
  "epss_score": 0.82882,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}