CVE-2024-27186Network attack vector

Script execution via unescaped mail template values

Published Aug 20, 2024 · Updated Nov 26, 2024

Cross-site scripting in Joomla! CMS 4.0.0 through 4.4.6 and 5.0.0 through 5.1.2 allows remote attackers to run script via HTML mail. MailTemplate::replaceTags substitutes extension-supplied values directly into HTML bodies without HTML-encoding attacker-controlled fields. Exploitation requires a recipient to render a crafted HTML message, allowing script execution in that recipient's mail-viewing origin with no availability impact reported.

CVSS severity6.1
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Joomla! CMS 4.0.0 through 4.4.6 and 5.0.0 through 5.1.2 allows remote attackers to run script via HTML mail. MailTemplate::replaceTags substitutes extension-supplied values directly into HTML bodies without HTML-encoding attacker-controlled fields. Exploitation requires a recipient to render a crafted HTML message, allowing script execution in that recipient's mail-viewing origin with no availability impact reported.

The record

CVE
CVE-2024-27186
Published
Aug 20, 2024
Updated
Nov 26, 2024
Vendor
Joomla! Project
Product
Joomla! CMS
Classifications
CWE-79, CAPEC-18, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 26, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.0.0-4.4.6
  2. Affected versionversion=5.0.0-5.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Joomla! Project · Joomla! CMSversion=4.0.0-4.4.6; version=5.0.0-5.1.2

Published CVSS scores

6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-18XSS Targeting Non-Script Elements
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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