Yes, there is a working jailbreak for 6.1.2. It has also been reported that 6.1.3 fixes the vulnerability that was used to jailbreak previous versions, so I recommend you do NOT upgrade to 6.1.3 when it comes out. Be sure to save all the SHSH blobs that you can using tinyumbrella. Do this ASAP, as it can only be done for a limited time. Check out www.jailbreaknation.com for more details and information on jailbreaking, including instructions.