When creepers are repelled by ocelots or cats, they can still attack. This is unlike phantoms when they're deterred by cats, or hoglins when they're deterred by warped fungi, portals, or respawn anchors.

To reproduce, create a small confine, spawn a creeper in the confine, place a sitting cat in the creeper's view, and notice that it will still hiss and blow up despite being deterred.