3DS:Is it safe to update?

The current firmware version is 11.17.0-50.

If the console already has CFW
Before the console can be updated, make sure Luma3DS is on the most recent version. To check its version, hold while turning on the console.

If the console does not yet have CFW
There is currently no free exploit for Old 3DS consoles.

New 3DS EUR/JPN consoles can use super-skaterhax. New 3DS USA consoles must wait for the otherapp payload to be updated.

Other exploits are available at 3DS:Alternate Exploits. Most of these depend on having certain games or a second console with custom firmware.

Any console on any version can be hacked with ntrboot, but this requires a compatible DS flashcart.