Medium severity · published Sep 15, 2026
CVE-2026-81896
Concrete CMS below version 9.5.3 is vulnerable to Stored XSS in Concrete CMS Form Submissions Report via Unescaped Question Label
5.4
CVSS
0.2%
EPSS
No
On KEV
Description
Concrete CMS before 9.5.3 does not apply HTML entity encoding to user-defined Form block question labels when rendering them as column headers in the Dashboard Form Submissions report (concrete/single_pages/dashboard/reports/forms/legacy.php). a rogue editor could store markup or script in a label that then executes in the browser of any administrator who opens the submissions report for the affected form, producing stored cross-site scripting in the Dashboard. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.4 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% 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, NVD
Affected product
CC
Concrete CMS
Concrete CMS
More from Concrete CMS
9.6
CVE-2026-85385
Concrete CMS below 9.5.4 is vulnerable to Stored XSS via User Timezone Field
9.0
CVE-2026-18119
Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values
8.8
CVE-2026-8409
Concrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/dialog/logs/delete
8.8
CVE-2026-8410
Concrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/dialog/logs/bulk/delete
8.8
CVE-2026-8411
Concrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/dialog/page/bulk/delete