Simple Gallery contains a flaw that allows a remote cross site scripting attack.  This flaw exists because the application does not validate the "album" variable upon submission to the index.php script.  This could allow a user to create a specially crafted URL that would execute arbitrary code in a user's browser within the trust relationship between the browser and the server, leading to a loss of integrity.

References:

BID: 28596

CVE-2008-1698  

OSVDB: 43984

Secunia: 29646

SecWatch