Definitely not old enough for CIO yet. At the same time--I would take a "walk don't run" approach to attending to him when he wakes up. Sometimes DD starts to cry and then falls right back to sleep (I'm not sure she's even waking up completely at these times). I'd give him a chance to fall back asleep on his own if he's just fussing, not crying. If he's not waking completely when he wakes--or he's waking but not full-on crying--it might make sense to have him in another room if this bothers you. But I'm not ready for that yet even though DD does bug me a lot with her night noises.
This may just have been a bad night, too, or he might be on one end or another of a growth spurt--see how things go the next few days.
This. DD makes a lot of noise at night and also during the day for naps. Until recently, I started picking her up whenever she stirred during her naps. Now, I wait until she is crying or has stayed awake a decent amount of time before I get her up. I can now tell the difference between her 'I'm tired and falling back asleep' cry and her 'Come get me now mom' cry. Turns out she was way over tired during the day and needs way more sleep than she was getting. This helps with over night sleeping and nap times as well.
Obviously, your LO is too young to cry it out, but I wouldn't rush in at every noise. Give them a chance to fall back asleep and if your LO does, then that's great! If not, then you can go get him.
Like the PP said, it may have just been a bad night for him (gas, over-tired, etc.) or could be going through a growth spurt. Good luck!