diff shows no significant difference between Drupal 7.2 and Drupal 7.3

So Drupal 7.3 allegedly is a security upgrade for Drupal 7.2. But when I ran a diff between the extracted archives from 7.2 and 7.3, I found no code differences. What gives? Is the 7.3 release really a security update, or did the actual security patch get left out, by any chance?

update Apparently I cannot attach any files on this formum, so I'm inlining the output file from the command `diff -u drupal-7.2 drupal-7.3`

diff -u drupal-7.2/CHANGELOG.txt drupal-7.3/CHANGELOG.txt
--- drupal-7.2/CHANGELOG.txt	2011-05-25 22:41:42.000000000 +0200
+++ drupal-7.3/CHANGELOG.txt	2011-06-30 03:12:24.000000000 +0200
@@ -1,4 +1,8 @@
 
+Drupal 7.3, 2011-06-29
+----------------------
+- Fixed security issue (Access bypass), see SA-CORE-2011-002.
+
 Drupal 7.2, 2011-05-25
 ----------------------
 - Added a default .gitignore file.
@@ -236,6 +240,9 @@
     * Added a locking framework to coordinate long-running operations across
       requests.
 
+Drupal 6.23-dev, xxxx-xx-xx (development release)
+-----------------------
+
 Drupal 6.22, 2011-05-25
 -----------------------
 - Made Drupal 6 work better with IIS and Internet Explorer.
Common subdirectories: drupal-7.2/includes and drupal-7.3/includes
Common subdirectories: drupal-7.2/misc and drupal-7.3/misc
Common subdirectories: drupal-7.2/modules and drupal-7.3/modules
Common subdirectories: drupal-7.2/profiles and drupal-7.3/profiles
Common subdirectories: drupal-7.2/scripts and drupal-7.3/scripts
Common subdirectories: drupal-7.2/sites and drupal-7.3/sites
Common subdirectories: drupal-7.2/themes and drupal-7.3/themes