Poisonous monster's relevant ability score.

[H_H_F_F]

I apologize if this is a dumb or obvious question. If a monster's poison has a listed DC, but it doesn't say on which ability score that DC is based, can it be assumed it's based on constitution?

[Zanos]

Yeah, it's in the SRD.

https://www.d20srd.org/srd/specialAbilities.htm#poison

[Remuko]

Natural poison/venom is always (afaik) 10 + 1/2 monster HD + Con + any bonuses from feats or racial bonuses