CVE-2026-68528

Medium

Description

Concrete CMS RSS Displayer block below version 9.5.3 rendered remote feed item titles without HTML escaping, resulting in stored cross-site scripting. An attacker able to control a title in a syndicated feed could execute script in the site origin for any visitor to the affected page, including administrators, without holding an account on that site. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

SeverityMedium

CVSS6.0

Exploit probability—

Product

Concrete CMS

PublishedSep 11, 2026

First seenSep 11, 2026

Weakness typeCWE-79Cross-site scripting (XSS)

How to fix

Vendor advisories

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

Affected products

Product	Affected versions	Fixed in
Concrete CMS Concrete CMS	5.0.0 ≤ v ≤ 9.5.2	—

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