With iOS 7 on the horizon, many rumblings have been surfacing lately about the possibility of an iOS 6.1.3 jailbreak. First there was UnthreadedJB, who after releasing an obscure iOS 5.1 jailbreak for CDMA enable iPhone 4's, claims to have an iOS 6.1.3 jailbreak. Those claims have never been solidified by any independent sources, so the verdict is definitely still out about its legitimacy.
But there's still hope. iOS hacker winocm, well known throughout the jailbreak community, took to twitter this morning to confirm that he has a binary for an iOS 6.1.3 untethered jailbreak.