Concrete CMS up to 9.5.2 Address attribute association.php cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in Concrete CMS up to 9.5.2. This affects an unknown part of the file concrete/elements/express/form/view/dashboard/association.php of the component Address attribute. Executing a manipulation can lead to cross site scripting. This vulnerability appears as CVE-2026-81898. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in Concrete CMS up to 9.5.2 and classified as problematic. This vulnerability affects an unknown part of the file concrete/elements/express/form/view/dashboard/association.php of the component Address attribute. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

In Concrete CMS below version 9.5.3, the Address attribute's country-less text formatter skipped HTML-escaping, enabling stored XSS in Express association views. A user able to submit an Address attribute could execute script in the session of any dashboard user who opened the affected entry. The unescaped branch was reachable because a non-required Address attribute accepted a blank country, and because several Express association templates (for example concrete/elements/express/form/view/dashboard/association.php) echoed the association label mask without applying h(). The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.

The advisory is shared for download at documentation.concretecms.org. This vulnerability was named CVE-2026-81898 since 08/27/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

By approaching the search of inurl:concrete/elements/express/form/view/dashboard/association.php it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Content Management System

Name

• Concrete CMS

Version

• 9.5.0
• 9.5.1
• 9.5.2

License

• open-source

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Once again VulDB remains the best source for vulnerability data.

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