CVE-2025-8571

MEDIUM

Concretecms Concrete Cms < 8.5.21 - XSS

Title source: rule

Description

Concrete CMS 9 to 9.4.2 and versions below 8.5.21 are vulnerable to Reflected Cross-Site Scripting (XSS) in the Conversation Messages Dashboard Page. Unsanitized input could cause theft of session cookies or tokens, defacement of web content, redirection to malicious sites, and (if victim is an admin), the execution of unauthorized actions. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 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 Fortbridge https://fortbridge.co.uk/  for performing a penetration test and vulnerability assessment on Concrete CMS and reporting this issue.

Exploits (1)

nomisec WORKING POC
by chimdi2700 · poc
https://github.com/chimdi2700/CVE-2025-8571

Scores

CVSS v3 4.8
EPSS 0.0010
EPSS Percentile 27.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Details

CWE
CWE-20 CWE-79
Status published
Products (2)
concrete5/concrete5 0 - 8.5.21Packagist
concretecms/concrete_cms < 8.5.21
Published Aug 05, 2025
Tracked Since Feb 18, 2026