CVE-2026-90906 — Joomla\!
HIGHCVE-2026-90906 is a high-severity (CVSS 8.3) Cross-site Scripting (XSS) vulnerability in joomla joomla\!. A fix is available — see the affected versions and patch details below.
Joomla! Core - [20260901] - XSS in HTMLHelper::link method in Joomla 1.5.0-5.4.8, 6.0.0-6.1.3 - Lack of escaping leads to XSS vulnerabilities in the link method of the HTML Helper.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-90906.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-90906 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 383,485 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Joomla! Core - [20260901] - XSS in HTMLHelper::link method in Joomla 1.5.0-5.4.8, 6.0.0-6.1.3 - Lack of escaping leads to XSS vulnerabilities in the link method of the HTML Helper.
Affected Products
joomla\!joomlaDetection & mitigation playbook
Vendor / applianceDetect
Inventory every joomla joomla\! deployment and check each version against the affected-products list above.
Fix
Apply the joomla joomla\! security patch or hotfix for CVE-2026-90906 on the affected version, following the vendor advisory for your exact build.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2026-90906 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.