The way URIs are handled in admin/header.php in Chadha PHPKB Standard Multi-Language 9 allows Reflected XSS (injecting arbitrary web script or HTML) in admin/manage-settings.php by adding a question mark (?) followed by the payload.
https://antoniocannito.it/phpkb1#reflected-cross-site-scripting-in-every-admin-page-cve-block-going-from-cve-2020-10391-to-cve-2020-10456
http://antoniocannito.it/?p=137#uxss
Source: Mitre, NVD
Published: 2020-03-12
Updated: 2026-06-17
Base Score: 3.5
Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N
Severity: Low
Base Score: 4.8
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
EPSS: 0.00235