Stored XSS in Concrete CMS via OAuth Integration Name

Publication date: 2026-05-21

Last updated on: 2026-05-26

Assigner: ConcreteCMS

Description

Concrete CMS 9.5.0 and below is vulnerable to Stored XSS via OAuth integration name. The OAuth authorize template renders the integration name (admin-controlled) through Concrete's t() translation helper as a sprintf-style format. The <strong>...</strong> wrap is built by PHP string interpolation before t() runs, so the integration name lands in the translated output as raw HTML. A rogue admin could potentially snoop on login submissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N Thanks Yonatan Drori (Tenzai) for reporting.

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Meta Information

Published

2026-05-21

Last Modified

2026-05-26

Generated

2026-07-02

AI Q&A

2026-05-22

EPSS Evaluated

2026-06-30

NVD

CVE-2026-8197

Affected Vendors & Products

Vendor	Product	Version / Range
concretecms	concrete_cms	to 9.5.0 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
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.

Attack-Flow Graph

Executive Summary

This vulnerability affects Concrete CMS version 9.5.0 and below. It is a Stored Cross-Site Scripting (XSS) issue that occurs via the OAuth integration name. Specifically, the OAuth authorize template renders the integration name, which is controlled by an admin, using Concrete's translation helper t() as a sprintf-style format. However, the integration name is inserted into the translated output as raw HTML because the <strong>...</strong> wrap is built by PHP string interpolation before the translation function runs. This allows a rogue admin to inject malicious scripts that could potentially snoop on login submissions.

Impact Analysis

The vulnerability can allow a rogue administrator to execute stored cross-site scripting attacks by injecting malicious code into the OAuth integration name. This could lead to unauthorized access to sensitive information, such as snooping on login submissions, potentially compromising user credentials or session data.

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