diff --git src/wp-admin/includes/misc.php src/wp-admin/includes/misc.php
index 679b9ac..480d2fb 100644
--- src/wp-admin/includes/misc.php
+++ src/wp-admin/includes/misc.php
@@ -109,6 +109,10 @@ function insert_with_markers( $filename, $marker, $insertion ) {
 		if ( ! touch( $filename ) ) {
 			return false;
 		}
+		// Make sure file is created with a minimum set of permissions.
+		if ( $perms = fileperms( $filename ) ) {
+			chmod( $filename, $perms | 0644 );
+		}
 	} elseif ( ! is_writeable( $filename ) ) {
 		return false;
 	}