What’s Vulnerable › Vulnerabilities

CVE-2026-21631: Joomla! Core - [20260303] - XSS vector in com_associations comparison view

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-04-01 · updated 2026-10-26
• Weakness: CWE-79

Description

Lack of output escaping leads to a XSS vector in the multilingual associations component.

Affected products

• Joomla!: from 3.0.0 before 5.4.4; from 6.0.0 before 6.0.4 — fixed in 5.4.4, 6.0.4

How to fix

Upgrade to a fixed version: Joomla! 5.4.4, 6.0.4. Check the vendor advisory for mitigations.

References

• https://developer.joomla.org/security-centre/1029-20260303-core-xss-vector-in-com-associations-comparison-view.html
• https://github.com/Shirshaw64p/security-advisories/tree/main/CVE-2026-21631

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