These users believed their consoles to be bricked by the offending message. Thankfully, this is not the case and you did not need to factory reset your console if you had fallen victim.
It seems as though Sony was quickly made aware of the issue and quickly issued a fix. The news comes from the PlayStation UK Twitter support account.
If you find it concerning that a simple text message could crash your console, it's actually a bit more common than you would think. Apple had a similar issue earlier this year with the iPhone. It also hit Android devices. An explanation of the issue as it applied to these devices back in May is best explained by Tom Scott.
At any rate, it's all fixed now. If your system is still crashing with something about an error in your system software, delete the message via the mobile app and follow the instructions outlined in the tweet above. You'll be right as rain in no time.