At some point during the past week or so, the evad3rs released an update for evasi0n7, bringing the jailbreak tool to version 1.0.8. According to the change log, the software now supports build 11A466 of iOS 7.
Apparently 11A466 is a factory build—not available for download—of the iOS 7 firmware that shipped on some of iPhone 5s and 5c units. And up until now, folks with these devices were having issues jailbreaking...