CVE-2026-81898

HighCVSS 7.5/10Last modified Sep 20, 2026

Description

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.

Metrics

CVSS 4.0 7.5/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weakness enumeration

CWE-79

Affected software

Source: the vendor's advisory (CNA). NVD analysis pending.

Vendor	Product	Versions
Concrete CMS	Concrete CMS	>= 5.0.0, <= 9.5.2

References

https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes

Timeline

Published: Sep 15, 2026
Last modified: Sep 20, 2026
NVD status: Awaiting Analysis

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