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

published 2026-05-21 5 mo ago modified 2026-09-10 1 mo ago also GHSA-f73j-pm2c-rxvr , EUVD-2026-31357

cvss: 5.4; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits: 0; none known

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

Patch / fix

fixed in 2

packagist concrete5/concrete5 9.5.1
concretecms concrete_cms 9.5.1

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-22)

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.0	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
CNA	4.0	6.0	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/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
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
packagist	concrete5/concrete5	<9.5.1	9.5.1

Affected products

Concrete CMS Concrete CMS

Classification

Weakness

CWE-83 Improper Neutralization of Script in Attributes in a Web Page

References

documentation.concretecms.org /9-x/developers/introduction/version-history/951-release-notes
release-notes, web
nvd.nist.gov /vuln/detail/CVE-2026-8245
advisory
github.com /concretecms/concretecms
package

Sources

CVE List CVE-2026-8245
GitHub Advisory GHSA-f73j-pm2c-rxvr
NVD CVE-2026-8245

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Summary