My team uses Passpack, but I found a few self-hosted solutions previously. I didn't test them, though.

TeamPass: A PHP app. Hosted or downloadable. http://www.teampass.net/

WebPasswordSafe: A Java web app. Uses Password Safe databases. https://code.google.com/p/webpasswordsafe/

corporatevault: A Grails web app. http://sourceforge.net/projects/corporatevault/

Clipperz: A JavaScript web app. Hosted or downloadable. Sharing support coming soon. http://www.clipperz.com/support/user_guide/sharing