CVE-2026-81918

MEDIUM CVSS 4.0: 4.8 EPSS 0.30%
Updated Sep 12, 2026
Payload
Parameter Value
CVSS 4.8 (MEDIUM)
Type CWE-79 (Cross-Site Scripting (XSS))
Vendor Payload
Public PoC No

Concrete CMS below 9.5.3 is vulnerable to Stored XSS via the Date Format field in the Page Attribute Display block. A user with edit_page_contents permissions could store a payload which executes in the browser of any visitor who viewed a page where the block was configured to display a date-type attribute. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N.

Thanks Oriol Ortiz for reporting.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
High
Admin privileges needed
User Interaction
Passive
Minimal interaction

Impact Assessment

Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption

CVSS Vector v4.0