Descripton: Escape late in get_avatar()
Author: nacin
Origin: vendor, https://core.trac.wordpress.org/changeset/29398
--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -1672,7 +1672,8 @@
 
 		$avatar = "<img alt='{$safe_alt}' src='{$out}' class='avatar avatar-{$size} photo' height='{$size}' width='{$size}' />";
 	} else {
-		$avatar = "<img alt='{$safe_alt}' src='{$default}' class='avatar avatar-{$size} photo avatar-default' height='{$size}' width='{$size}' />";
+		$out = esc_url( $default );
+		$avatar = "<img alt='{$safe_alt}' src='{$out}' class='avatar avatar-{$size} photo avatar-default' height='{$size}' width='{$size}' />";
 	}
 
 	return apply_filters('get_avatar', $avatar, $id_or_email, $size, $default, $alt);
