There are some Tomcat security vulnerabilities reported against the bundled version 7.0.32:
[CVE-2013-2067|http://mail-archives.apache.org/mod_mbox/www-announce/201305.mbox/<[email protected]>]
[CVE-2013-2071|http://mail-archives.apache.org/mod_mbox/tomcat-announce/201305.mbox/<[email protected]>]
[CVE-2012-3544|http://mail-archives.apache.org/mod_mbox/tomcat-announce/201305.mbox/<[email protected]>] - Not reported for Tomcat 7.0.32
Stash should be bundled with the latest Tomcat version 7.0.40 to ensure it contains a fix for the above security vulnerabilities.