diff --git a/system/core/Security.php b/system/core/Security.php
index 7c51992..8ca66d2 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -787,11 +787,11 @@
 			$count = $temp_count = 0;
 
 			// replace occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes)
-			$str = preg_replace('/(<[^>]+)(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', '$1[removed]', $str, -1, $temp_count);
+			$str = preg_replace('/<([^>]+((?<=\042)[^\042]*(?=\042)|(?<=\047)[^\047]*(?=047))*[^>]*)(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\4]*?)(\\4)/is', '<$1[removed]', $str, -1, $temp_count);
 			$count += $temp_count;
 
 			// find occurrences of illegal attribute strings without quotes
-			$str = preg_replace('/(<[^>]+)(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', '$1[removed]', $str, -1, $temp_count);
+			$str = preg_replace('/<([^>]+((?<=\042)[^\042]*(?=\042)|(?<=\047)[^\047]*(?=047))*[^>]*)(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', '<$1[removed]', $str, -1, $temp_count);
 			$count += $temp_count;
 		}
 		while ($count);