"More efficient" of course has many axes (cost, energy consumption, manual labor requirement vs cost of human, time, quality, etc.). However, as a long-time reverse engineer and exploit developer who has worked in the field professionally, I would say LLMs are now useful; their utility exceeds that which was previously available. That is, LLM assisted exploit discovery and especially development is faster, more efficient, and ultimately cheaper than non-LLM assisted processes.

What commenters don't seem to understand is that especially CVE spam / bug bounty type vulnerability research has always been an exercise in sifting through useless findings and hallucinations, and LLMs, used well, are great at reducing this burden.

Previously, a lot of "baseline" / bottom tier research consisted of "run fuzzers or pentest tools against a product; if you're a bottom feeder just stuff these vulns all into the submission box, if you're more legit, tediously try to figure out which ones are reachable." LLMs with a test harness do an _amazing_ job at reducing this tedium; in the memory safety space "read across 50 files to figure out if this UAF might be reachable" or in the web space, "follow this unsanitized string variable to see if it can be accessed by the user" are tasks that LLMs with a harness are awesome. The current models are also about 50% there at "make a chain for this CVE," depending on the shape of the CVE (they usually get close given a good test harness).

It seems that the concern with the unreleased models is pretty much that this has advanced once again from where it is today (where you need smart prompting and a good harness) to the LLM giving you exploit chains in exchange for "giv 0day pl0x," and based on my experience, while this has got an element of puffery and classic capitalist goofiness to it ("the model is SO DANGEROUS only our RICHEST CUSTOMERS can have it!"), I believe this is just a small incremental step and entirely believable.

To summarize: "more efficient than all but the best" comes with too many qualifiers, but "are LLMs meaningfully useful in exercising vulnerabilities in OS kernel code," or "is it possible to accelerate vulnerability research and development with LLMs" - 100% absolutely.

And you don't have to believe one random professional (me); this opinion is fairly widespread across the community:

https://sockpuppet.org/blog/2026/03/30/vulnerability-researc...

https://lwn.net/Articles/1065620/

etc.