Poisonous broccoli??

I had leftover broccoli and cauliflower mix bag, I was going to give cauliflower and asked alexa and she said both Broccoli and Cauliflower are poisonous to rabbits?? He eats broccoli in moderation often?

I swiped that cauliflower away before he could eat any and gave Kale instead, but now I'm confused. He's at least age 5.