CVE-2025-8571

MEDIUM

Concrete CMS < 8.5.21 and 9.0.0-9.4.2 - Reflected Cross-Site Scripting in Conversation Messages Dashboard Page

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2025-8571. PoCs published by chimdi2700.

AI-analyzed exploit summary This repository contains a functional Python exploit for CVE-2025-8571, targeting a JWT authentication bypass in a WordPress plugin. The script generates a crafted JWT token to impersonate a user and modify their details via an API endpoint.

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

This repository contains a functional Python exploit for CVE-2025-8571, targeting a JWT authentication bypass in a WordPress plugin. The script generates a crafted JWT token to impersonate a user and modify their details via an API endpoint.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: WordPress plugin (likely related to grind-mobile-app)
No auth needed
Prerequisites: Target URL · User ID to impersonate
devstral-2 · analyzed Feb 18, 2026 Full analysis →

Scores

CVSS v3 4.8
EPSS 0.0026
EPSS Percentile 49.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

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