Merge pull request #5391 from mehdibo/fix/url-helper

Prevent tab hijacking when using the URL helper
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 0359ac9..a22c4c2 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -396,7 +396,7 @@
 		if ($type !== 'email' && preg_match_all('#(\w*://|www\.)[a-z0-9]+(-+[a-z0-9]+)*(\.[a-z0-9]+(-+[a-z0-9]+)*)+(/([^\s()<>;]+\w)?/?)?#i', $str, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER))
 		{
 			// Set our target HTML if using popup links.
-			$target = ($popup) ? ' target="_blank"' : '';
+			$target = ($popup) ? ' target="_blank" rel="noopener"' : '';
 
 			// We process the links in reverse order (last -> first) so that
 			// the returned string offsets from preg_match_all() are not