The common flu is a lot more dangerous than CRISPR/cas9.
The CRISPR/cas9 system has potential for existential threat in the same way that AI does (not anytime soon.) This is what happens when you develop a new set of tools.
"And Ye Shall Know the Truth and the Truth Shall Make You Free" is inscribed in the lobby of the CIA, but informally they say "the truth will just make you nervous". :(
The potential dangers from gene editing shouldn't be put in the same light as artificial intelligence or nuclear technologies. Instead it deserves recognition for the nature of its actual danger, that being it's ease of use as mentioned, potential uses (of which I don't believe the tip of the iceberg has been reached), and as far as a risk of existential threat is concerned, it's communicability.
Gene-editing will not be a nuclear arms race nor will it be a speculative threat as AI currently stands. Gene-editing can be put into action by anyone, just as an AI of some sort might be, but has very real consequences, just as nuclear technology does.
"All biowarfare laboratories - and indeed, many ordinary biotech labs – thus represent an ongoing existential threat to humanity whose safety, like that of nuclear materials, cannot ever be guaranteed.
"This was highlighted in early 2016 when James Clapper, U.S. director of national intelligence, issued a warning that even gene editing (such as by the technology known as CRISPR) should be added to the list of weapons of mass destruction, adding that it 'increases the risk of the creation of potentially harmful biological agents or products'. (Regalado 2016). Other scientists warned that genetically modified lifeforms could be used to target specific groups of humans carrying certain genes, or if released in agricultural ‘designer crops’ might result in uncontrollable plagues. They cautioned that gene editing technology is far cheaper and easier to access than nuclear or chemical weapons."
- Surviving the 21st Century, Julian Cribb, Chapter 8 "The Urbanite (Homo urbanus)"