From 67e2b328163f63af0949b54c023206e6fbab6aa6 Mon Sep 17 00:00:00 2001
From: Marc Alexander <admin@m-a-styles.de>
Date: Sat, 15 Feb 2025 20:21:25 +0100
Subject: [PATCH] [ticket/17326] Ignore invalid class names

PHPBB-17326
---
 phpBB/adm/style/admin.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/phpBB/adm/style/admin.js b/phpBB/adm/style/admin.js
index f308bf9c12..3d37b0c331 100644
--- a/phpBB/adm/style/admin.js
+++ b/phpBB/adm/style/admin.js
@@ -280,6 +280,12 @@ function parse_document(container)
 
 		// Live update BBCode font icon preview
 		const updateIconClass = (element, newClass) => {
+			// Ignore invalid class names
+			const faIconRegex = /^(?!-)(?!.*--)[a-z0-9-]+(?<!-)$/;
+			if (!faIconRegex.test(newClass)) {
+				return;
+			}
+
 			element.classList.forEach(className => {
 				if (className.startsWith('fa-') && className !== 'fa-fw') {
 					element.classList.remove(className);