My first ever was Stripe CTF in 2012 I think, I still wear the shirt I got (now super fainted) from passing some challenges.
I was a student in portugal and remember receiving the shirt for it and thinking, maybe those Americans aren't any better than me and I can compete at the same level.
I never got super into security but it gave me the confidence to play in the same field and lose the stupid aura I had that somehow "rich americans" would be better than me at everything because they had better universities or because of Hollywood or something.
Sad that another cool thing is lost to AI but I guess kids will learn in other ways.
I have normally found any sort of timed technical competition intimidating. Even so, about 6 or 7 years ago, after being persuaded by a colleague, I participated in a few CTFs. I am glad I did, back when this type of thing still meant something. I have kept a screenshot from one of the CTFs that I am quite fond of: https://susam.net/files/blog/ctf-2019.png
In addition to what others have said, this usage is very common in the CTF world. "The challenge has no solves", "We just got the first solve" etc are very idiomatic. It would actually look weird to me if this was "solution".
I don't do CTF's but took part at the security workshop for fun ~2 years with my Android phone only. I was first with the first simple challenge, but then couldnt continue because my phone was just too limited. But I watched what the others did. And a young Indian guy did everything with ChatGPT then. I found it silly, but amusing, because he actually got second. There was no Codex nor Claude then. Nowadays it must be dead for real, because I would solve everything with my agents, as I do in the real world.
Okay, but none of that is actually responsive to what the article is discussing, which is competitive CTFs. There's not a single criticism of using AI for actual security research in anything they wrote and they mention being a heavy user of GPT-5.5 and GPT-5.5 Pro so belittling the author's experience to defend LLMs wasn't actually necessary.
I was writing an obfuscator recently, I just had the model deobfuscate and optimize the code back to original and I kept improving the obfuscator until it couldn't. The funny thing is that after all this I also ended up with a really strong deobfuscator and optimizer which is probably more capable than most commercial tools.
The solution is just to make CTFs harder, but when do CTFs become too hard? Maybe the problem is that 'hard' CTFs are fundementally too 'simple' where it's just a logic chain and an exhaustive bruteforce towards a solution since there really are limited ways to express a solution in plain sight.
Or maybe human creativity has been exhausted and we're not so limitless as we thought. Only time will tell.
I had another idea spring to mind: we could hide two flags, one that could only be found by ai agents and not humans or tools written by humans.
I don’t think CTFs are dead, they’ll just evolve. The difficulty level will need to be increased or the rules locked down. Just like sports and racing persist despite the existence of performance enhancing drugs and rocket technology.
I just did a CTF where I was in the top 10. It was the first CTF I completed and I used AI because the rules permitted it. That said, I couldn’t solve all challenges.
But yes, it was significantly easier now than I last attempted one. Even manually solving with AI assisted assembly interpretation was much easier.
Interesting and well written article that mirrors/foreshadows how LLMs do and will change other scenes.
As I don't know much about the CTF scene, I looked for other takes on this topic.
Here's an article from 2015 about how tool-assistance already changed CTFs:
> Individual skill will undoubtedly be a factor next year. But, I'm left wondering whether next year's DEFCON CTF will tell us anything more than how well-developed each team's tools are (and how well they can interpret the results).
And here's someone explaining how Claude Max allowed them to win CTFs:
> I had always been interested in CTF as one of the only ways people could compete and show off their skill in coding/problem solving on a global scale. It was just too difficult and didn't make sense for me to learn the fundamentals as an electrical engineer. As time went on, I got better and better, and it was hard to tell whether it was because of experience or if it was because of improvements in AI.
> I accomplished my goals, and for that reason I'm quitting CTF, at least for now. [...] I'd like to think I highlighted the problem before it became a bigger issue. So, how do we fix this? Teams and challenge authors losing motivation is not good. CTF dying is not good. AI bad. Or is it?
The only article that saw LLMs as a non-negative force for CTFs was this one. Fittingly, it sounds like LLM output ("Let's be honest", "This is where things get interesting.") and only contains hallucinated references.
I'm conflicted on the use of AI in CTFs. On the one hand, they are supposed to mirror real-life scenarios, so of course you should be able to use any tool that would be available to you in real life.
On the other hand, CTFs are fundamentally a game and a competition which are supposed to be fun and compare and improve ones skill. So when I let an LLM generate the entire solution for me, what's the point anymore? I did not learn anything. I did not work for that place on the leaderboard, I just copied the solution. And worst of all, I did not have any fun. It's boring.
So how does using AI as a solver not feel like cheating?
Replace ‘CTF’ with ‘high school’ or ‘university’ and you’ve described the total slow motion collapse of education; the only saving grace is that most of it requires in person presence.
We’ve figured out the human replacement pipeline it seems, but we haven’t figured out the eduction part. LLMs can be wonderful teachers, but the temptation to just tell it ‘do it for me’ is almost impossible to resist.
> Replace ‘CTF’ with ‘high school’ or ‘university’ and you’ve described the total slow motion collapse of education; the only saving grace is that most of it requires in person presence.
So something like, "Frontier AI has broken the 'high school' or 'university' format"?
The hype surrounding AI is just pervasively exhausting: you've got the folks talking about an entire new age for humanity where we're shortly going to take over the entire universe. And you've got the folks talking about how our entire society is crumbling.
Education is one place folks seem to throw up their hands and say nothing can be done.
The fix is simple: students are to be evaluated on their performance in person. That's it.
Any other "collapse of education" isn't due to AI, it's something else.
I started teaching “how to build quality products using LLMs” full time recently, and most of what I teach is literally just the 101s of systems engineering, reliabily engineering, product development and project management:
Exceptional clarity on the problem you have
Know how to measure the problem you’re solving
Numerically define what “done” is
Make a deterministic and fully observable prototype
Iterate in production with the user
Expand user base as desired with user iteration in parallel forever
Etc…
Obviously a lot more in the details and these are all case by case, but these chatbots are basically perfect productivity machines for this process.
The massive caveat to all of this is this only works for people that can reliably and truthfully define those items above, are willing to structure organization to make those your priorities.
And actually most financial incentives demand the opposite of this process
If most organizations were honest about it, they would simply say “we’re here to make the most money possible and we’re gonna do whatever it takes to do that”
A lot of people don’t like that, so they don’t say it to come up with other bullshit.
Ultimately that’s why I felt like my only option right now is to teach people how to do this because I assumed it was obvious and it is not.
Great article, well written, and good analogy to chess. I’ve been playing competitive chess most of my adult life and I think that the solution lies in how chess dealt with this problem:
Explicit ELO measurements with some cheating detection. AI assistance wholly banned. As you climb the ELO ladder, detection gets more onerous. At top level during online events, anti cheating teams require the use of both monitoring software and multiple cameras.
Idea is that you can cheat pretty easily at the lowest levels but it gets less easy the higher you go. This allows for better feeding into the truly elite competitions.
I think chess’s very firm stance that AI is never allowed in competition (neither online nor in person), rather than CTF’s acceptance, was the right call.
«That feedback loop is breaking. If the visible scoreboard is dominated by teams using AI, a beginner is pushed toward using AI before they have built the instincts the AI is replacing. That is an anti-pattern. It prevents active learning, and active struggle is the bit that actually teaches you. It is also completely demotivating to put in real effort and see no visible progress because the ladder above you has been automated.»
This stands out to me, and speaks perhaps broader than the article itself? I’m sure this has been in the spotlight before, but well put for many areas I think.
Meta: this was submitted with the article’s title “The CTF scene is dead” which I found very easy to understand. It has just been updated to use the subtitle’s first sentence, “Frontier AI has broken the open CTF format”. I find that much harder to grasp, rather like a garden-path sentence. My immediate thoughts were that “Frontier” was a company name, and that there was some file format named CTF. If you don’t know about Capture The Flag contests, the change doesn’t help. If you do, I think the change makes it worse.
I agree, it took me a second to parse. It may be because this is the first time I've seen "frontier models" described as "Frontier AI". That sounds more like a company name, especially when the F is capitalized.
Frontier as in "Frontier Model" is a legitimate vocabulary term you should probably be aware of in 2026. It's not something the author made up or chose randomly, it's common parlance in the space.
103 comments
[ 4.1 ms ] story [ 92.4 ms ] thread>and the old game is not coming back
For many people the CTF scene was already dead in 2021 because it had turned into something unrecognisable.
In reality it’s just different.
still has no mention of AI, but that will likely change as they increasingly dominate competition.
I never got super into security but it gave me the confidence to play in the same field and lose the stupid aura I had that somehow "rich americans" would be better than me at everything because they had better universities or because of Hollywood or something.
Sad that another cool thing is lost to AI but I guess kids will learn in other ways.
It's an incredibly exciting time in security research in my humble old man opinion.
Think the cadence of new exploits is perhaps a good measure of that rather than subjective thoughts by anyone regardless of experience.
The solution is just to make CTFs harder, but when do CTFs become too hard? Maybe the problem is that 'hard' CTFs are fundementally too 'simple' where it's just a logic chain and an exhaustive bruteforce towards a solution since there really are limited ways to express a solution in plain sight.
Or maybe human creativity has been exhausted and we're not so limitless as we thought. Only time will tell.
I had another idea spring to mind: we could hide two flags, one that could only be found by ai agents and not humans or tools written by humans.
I just did a CTF where I was in the top 10. It was the first CTF I completed and I used AI because the rules permitted it. That said, I couldn’t solve all challenges.
But yes, it was significantly easier now than I last attempted one. Even manually solving with AI assisted assembly interpretation was much easier.
As I don't know much about the CTF scene, I looked for other takes on this topic.
Here's an article from 2015 about how tool-assistance already changed CTFs:
> Individual skill will undoubtedly be a factor next year. But, I'm left wondering whether next year's DEFCON CTF will tell us anything more than how well-developed each team's tools are (and how well they can interpret the results).
https://fuzyll.com/2015/ctf-is-dead-long-live-ctf/
But there are quite a few recent (2026) articles with the same core message as in the original article, e.g., https://blog.includesecurity.com/2026/04/ctfs-in-the-ai-era/ or https://k3ng.xyz/blog/ctf-is-dead
And here's someone explaining how Claude Max allowed them to win CTFs:
> I had always been interested in CTF as one of the only ways people could compete and show off their skill in coding/problem solving on a global scale. It was just too difficult and didn't make sense for me to learn the fundamentals as an electrical engineer. As time went on, I got better and better, and it was hard to tell whether it was because of experience or if it was because of improvements in AI.
> I accomplished my goals, and for that reason I'm quitting CTF, at least for now. [...] I'd like to think I highlighted the problem before it became a bigger issue. So, how do we fix this? Teams and challenge authors losing motivation is not good. CTF dying is not good. AI bad. Or is it?
https://blog.krauq.com/post/ctf-is-dying-because-of-ai
The only article that saw LLMs as a non-negative force for CTFs was this one. Fittingly, it sounds like LLM output ("Let's be honest", "This is where things get interesting.") and only contains hallucinated references.
https://caverav.cl/posts/ctfs-not-dead/ctfs-not-dead/
The whole point of competitions is to provide a safe environment thanks to a set of rules all participants AGREE on in order to progress together.
If new tools "break" the competition, we change the rules and that's A-OK.
CTF isn't a natural phenomenon, if tools change, rules change, simple.
On the other hand, CTFs are fundamentally a game and a competition which are supposed to be fun and compare and improve ones skill. So when I let an LLM generate the entire solution for me, what's the point anymore? I did not learn anything. I did not work for that place on the leaderboard, I just copied the solution. And worst of all, I did not have any fun. It's boring.
So how does using AI as a solver not feel like cheating?
We’ve figured out the human replacement pipeline it seems, but we haven’t figured out the eduction part. LLMs can be wonderful teachers, but the temptation to just tell it ‘do it for me’ is almost impossible to resist.
So something like, "Frontier AI has broken the 'high school' or 'university' format"?
The hype surrounding AI is just pervasively exhausting: you've got the folks talking about an entire new age for humanity where we're shortly going to take over the entire universe. And you've got the folks talking about how our entire society is crumbling.
Education is one place folks seem to throw up their hands and say nothing can be done.
The fix is simple: students are to be evaluated on their performance in person. That's it.
Any other "collapse of education" isn't due to AI, it's something else.
Exceptional clarity on the problem you have
Know how to measure the problem you’re solving
Numerically define what “done” is
Make a deterministic and fully observable prototype
Iterate in production with the user
Expand user base as desired with user iteration in parallel forever
Etc…
Obviously a lot more in the details and these are all case by case, but these chatbots are basically perfect productivity machines for this process.
The massive caveat to all of this is this only works for people that can reliably and truthfully define those items above, are willing to structure organization to make those your priorities.
And actually most financial incentives demand the opposite of this process
If most organizations were honest about it, they would simply say “we’re here to make the most money possible and we’re gonna do whatever it takes to do that”
A lot of people don’t like that, so they don’t say it to come up with other bullshit.
Ultimately that’s why I felt like my only option right now is to teach people how to do this because I assumed it was obvious and it is not.
Explicit ELO measurements with some cheating detection. AI assistance wholly banned. As you climb the ELO ladder, detection gets more onerous. At top level during online events, anti cheating teams require the use of both monitoring software and multiple cameras.
Idea is that you can cheat pretty easily at the lowest levels but it gets less easy the higher you go. This allows for better feeding into the truly elite competitions.
I think chess’s very firm stance that AI is never allowed in competition (neither online nor in person), rather than CTF’s acceptance, was the right call.
This stands out to me, and speaks perhaps broader than the article itself? I’m sure this has been in the spotlight before, but well put for many areas I think.
Basic rule: define every abbreviation when it is first used.