iOS 9.3.5 downgrade
Downgrading iOS 9.3.5 to iOS 9.3.3 looks plausible for jailbreakers thanks to new re-restore tool

Apple has long been battling hard to discourage the jailbreak community by patching up all known exploits in its subsequent iOS firmware updates, while some veteran jailbreak developers have always been discovering new ways to circumvent the problem. A couple of new hackers, @alitek123 and @Thmitt, have jumped to the rescue of 32-bit iPhones running iOS 9.3.5 as the firmware does not have a working jailbreak till date.

Owners of older 32-bit iPhones can now effectively downgrade iOS 9.3.5 to iOS 9.3.3 in order to fancy an opportunity of jailbreaking their device with either Pangu or Home Depot. On the downside, their re-restore tool is limited to macOS and will not work on Windows.

The hackers have released the full list of requirements in order to be able to downgrade the iOS 9.3.5 firmware to a jailbreakable version:

Q: Does this need blobs?
A: Yes, blobs are required.
Q: What if I don't have blobs?
A: You're out of luck then. Sorry.
Q: What devices does this method work on?
A: Any 32 bit device running any iOS 9.x version.
Q: Do I have to be on iOS 9.3.5 to trigger this bug?
A: No. The bug exists on any iOS 9.x version.
Q: What if my iOS device is on iOS 10.x?
A: You're also out of luck then. Sorry.
Q: Any ETA?
A: I don't necessarily like giving ETA's out, but I feel kind of confident about this one. Expect something either at the end of this month or sometime in April.

[Source: Twitter via Redmond Pie]