Concrete CMS version 9 below 9.2.8 and previous versions below 8.5.16 is vulnerable to Stored XSS in blocks of type file. Stored XSS could be caused by a rogue administrator adding malicious code to the link-text field when creating a block of type file. The Concrete CMS security team gave this vulnerability a CVSS v3.1 score of 3.1 with a vector of AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:L/A:L https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator . Thanks Alexey Solovyev for reporting.

Concrete CMS Stored XSS in blocks of type file