Vulnerability · Published May 21, 2026 · Assigned by ConcreteCMS

CVE-2026-8245Concrete CMS 9.5.0 and below is vulnerable to Reflected XSS in Legacy Pagination via HTML attribute injection

Medium 6.0

In plain English

A medium-severity security flaw in Concrete CMS from Concrete CMS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.0Medium
Exploit odds (30 days)0.1%top 96.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Concrete CMS 9.5.0 and below is vulnerable to Reflected XSS in Legacy Pagination via HTML attribute injection. Concrete\Core\Legacy\Pagination builds pagination links by raw-interpolating its $URL field into href="" (<a href="{$linkURL}" …>). Any authenticated admin or report viewer with access to `/dashboard/reports/forms/legacy` who clicks the crafted URL fires the payload in their session. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.0 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Packagistconcrete5/concrete59.5.1GHSA-f73j-pm2c-rxvr

Affected products (as reported)

VendorProductVersions
Concrete CMS Concrete CMS 5.0 – through 9.5.0

Weakness: CWE-83 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

References