Medium severity · published Sep 11, 2026
CVE-2026-68528
Concrete CMS 9.5.2 and below is vulnerable to Stored XSS in RSS Displayer Block via Unescaped Remote Feed Item title
6.0
CVSS
0.4%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CC
Concrete CMS · Concrete CMS
5.0.0 through 9.5.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-68528
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-68528
documentation.concretecms.org
https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes
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