XSS in Concrete Cms
CVE-2025-8571
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.003 (24.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Concrete Cms — versions 9.0.0, 5.6
- Concretecms Concrete_cms
Weakness classification (CWE)
Public proof-of-concept exploits
References
- ff5b8ace-8b95-4078-9743-eac1ca5451de (Release Notes)
- ff5b8ace-8b95-4078-9743-eac1ca5451de (Release Notes)
- ff5b8ace-8b95-4078-9743-eac1ca5451de (Product)
Frequently asked questions
- What is CVE-2025-8571?
- CVE-2025-8571 is a medium-severity vulnerability in Concrete Cms, classified under Improper Input Validation. CVSS score: 4.8/10. Published 2025-08-05.
- How severe is CVE-2025-8571?
- Medium severity. CVSS v3 base score is 4.8 out of 10.
- Is CVE-2025-8571 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.