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…

PriorityP419medium4.8CVSS 3.1

AVNACLPRHUIRSCCLILAN

EPSS

0.30%

22.1th percentile

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.

Affected

6 ranges

Vendor	Product	Version range	Fixed in
concrete5	concrete5	>= 0 < 8.5.21	8.5.21
concrete5	concrete5	>= 9.0.0RC1 < 9.4.3	9.4.3
concrete_cms	concrete_cms	>= 5.6 < 8.5.21	8.5.21
concrete_cms	concrete_cms	>= 9.0.0 < 9.4.3	9.4.3
concretecms	concrete_cms	< 8.5.21	8.5.21
concretecms	concrete_cms	>= 9.0 < 9.4.3	9.4.3

CVSS provenance

nvdv3.14.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

nvdv4.04.8MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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