That’s just clearly untrue for freely available software. So every person that ever published a hobby project on GitHub has a duty to fix security issues in it?
The organisation who ships software to paying customer may have a duty to fix security issues. If they didn’t, it could be seen as negligent, violate regulations or the contract they have with their customers. But there’s no contract with the free software developers. No duty of care from them to end users. Absolutely no duty.