Steven De Franco, the nickname is iH8sn0w in the jailbreak community, successfully demonstrate iOS 10 jailbreak recently. This iOS 10 jailbreak demonstrate done by his iPhone 5 device.
So with this demonstrate iH8sn0w hinted to other jailbreak developers, still Apple all latest iOS versions are jailbreakable.
See iH8sn0w iOS 10 jailbreak demonstrate video and associate Twitter messages of iOS 10 jailbreak.
The previous jailbreak demonstrations of iH8sn0w
Apple killed iOS 9 jailbreak and iOS 8.1 jailbreak with iOS 8.4.1 update and iOS 8.1.1 update. Even Apple introduce Rootless jailbreak (jailbreak prevent) security update from iOS 9 version. So these time all jailbreak developers could not be able to release proper jailbreak solution for iOS 9 and iOS 8.1.1.