diff --git a/src/Core/Theme.php b/src/Core/Theme.php
index 5479f8f46f..02ffe3ada4 100644
--- a/src/Core/Theme.php
+++ b/src/Core/Theme.php
@@ -16,6 +16,23 @@ require_once 'boot.php';
  */
 class Theme
 {
+	public static function getAllowedList()
+	{
+		$allowed_themes_str = Config::get('system', 'allowed_themes');
+		$allowed_themes_raw = explode(',', $allowed_themes_str);
+		$allowed_themes = [];
+		if (count($allowed_themes_raw)) {
+			foreach ($allowed_themes_raw as $theme) {
+				$theme = Strings::sanitizeFilePathItem(trim($theme));
+				if (strlen($theme) && is_dir("view/theme/$theme")) {
+					$allowed_themes[] = $theme;
+				}
+			}
+		}
+
+		return $allowed_themes;
+	}
+
 	/**
 	 * @brief Parse theme comment in search of theme infos.
 	 *