CVE-2024-21731Network attack vector

Browser script execution via unsafe text truncation

Published Jul 9, 2024 · Updated Mar 14, 2025

Cross-site scripting in Joomla! CMS 3.0.0 through 3.10.15, 4.0.0 through 4.4.5, and 5.0.0 through 5.1.1 allows remote attackers to run script. StringHelper::truncate improperly handles untrusted input when shortening text, leaving an XSS vector in its output; Joomla has not published the faulty transformation. Exploitation requires a Joomla rendering path to pass attacker-controlled text to this helper and a user to view the resulting page, allowing script execution in that user's browser context.

CVSS severity6.1
Medium
EPSS probability0.44%
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 3.0.0 through 3.10.15, 4.0.0 through 4.4.5, and 5.0.0 through 5.1.1 allows remote attackers to run script. StringHelper::truncate improperly handles untrusted input when shortening text, leaving an XSS vector in its output; Joomla has not published the faulty transformation. Exploitation requires a Joomla rendering path to pass attacker-controlled text to this helper and a user to view the resulting page, allowing script execution in that user's browser context.

The record

CVE
CVE-2024-21731
Published
Jul 9, 2024
Updated
Mar 14, 2025
Vendor
Joomla! Project
Product
Joomla! CMS
Classifications
CWE-79, CAPEC-18
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Mar 14, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=3.0.0-3.10.15
  2. Affected versionversion=4.0.0-4.4.5
  3. Affected versionversion=5.0.0-5.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Joomla! Project · Joomla! CMSversion=3.0.0-3.10.15; version=4.0.0-4.4.5; version=5.0.0-5.1.1

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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