bool silly_mistake = false;
  
  //... lots of lines of code

  free(x);

  //... lots of lines of code

  if (silly_mistake) { // silly_mistake shown to be false at this point in the program in all testing, so far
     free(x);
  }

FWIW there's a whole boutique industry around finding these. People have built whole careers around farming bug bounties for bugs like this. I think they will be among the first set of software engineers really in trouble from AI.

This is not a surprise or a gotcha.

No state-sponsored hacking affected Americans materially. I just don't think we were networked enough in the 2010s. The risk is higher now since we're in a more warmongering world. (Kompromat on a power-plant technician is a risk in peace. It means blackouts in war.)

The fact that Iran hasn't been able to do diddly squat in America should sink in the fact that they didn't compromise us. (EDIT: blep. I was wrong.)

It isn't.

It will likely cause some interesting tensions with government as well.

eg. Apple's official stance per their 2016 customer letter is no backdoors:

https://www.apple.com/customer-letter/

Will they be allowed to maintain that stance in a world where all the non-intentional backdoors are closed? The reason the FBI backed off in 2016 is because they realized they didn't need Apple's help:

https://en.wikipedia.org/wiki/Apple%E2%80%93FBI_encryption_d...

What happens when that is no longer true, especially in today's political climate?

Benchmarks look very impressive! even if they're flawed, it still translates to real world improvements

---

Teodor painted signs for forty years in the same shop on Vell Street, and for thirty-nine of them he was angry about it.

Not at the work. He loved the work — the long pull of a brush loaded just right, the way a good black sat on primed board like it had always been there. What made him angry was the customers. They had no eye. A man would come in wanting COFFEE over his door and Teodor would show him a C with a little flourish on the upper bowl, nothing much, just a small grace note, and the man would say no, plainer, and Teodor would make it plainer, and the man would say yes, that one, and pay, and leave happy, and Teodor would go into the back and wash his brushes harder than they needed.

He kept a shelf in the back room. On it were the signs nobody bought — the ones he'd made the way he thought they should be made, after the customer had left with the plain one. BREAD with the B like a loaf just risen. FISH in a blue that took him a week to mix. Dozens of them. His wife called it the museum of better ideas. She did not mean it kindly, and she was not wrong.

The thirty-ninth year, a girl came to apprentice. She was quick and her hand was steady and within a month she could pull a line as clean as his. He gave her a job: APOTEK, for the chemist on the corner, green on white, the chemist had been very clear. She brought it back with a serpent worked into the K, tiny, clever, you had to look twice.

"He won't take it," Teodor said.

"It's better," she said.

"It is better," he said. "He won't take it."

She painted it again, plain, and the chemist took it and paid and was happy, and she went into the back and washed her brushes harder than they needed, and Teodor watched her do it and something that had been standing up in him for thirty-nine years sat down.

He took her to the shelf. She looked at the signs a long time.

"These are beautiful," she said.

"Yes."

"Why are they here?"

He had thought about this for thirty-nine years and had many answers and all of them were about the customers and none of them had ever made him less angry. So he tried a different one.

"Because nobody stands in the street to look at a sign," he said. "They look at it to find the shop. A man a hundred yards off needs to know it's coffee and not a cobbler. If he has to look twice, I've made a beautiful thing and a bad sign."

"Then what's the skill for?"

"The skill is so that when he looks once, it's also not ugly." He picked up FISH, the blue one, turned it in the light. "This is what I can do. What he needs is a small part of what I can do. The rest I get to keep." She thought about that. "It doesn't feel like keeping. It feels like not using."

"Yes," he said. "For a long time. And then one day you have an apprentice, and she puts a serpent in a K, and you see it from the outside, and it stops feeling like a thing they're taking from you and starts feeling like a thing you're giving. The plain one, I mean. The plain one is the gift. This —" the blue FISH — "this is just mine."

The fortieth year he was not angry. Nothing else changed. The customers still had no eye. He still sometimes made the second sign, after, the one for the shelf. But he washed his brushes gently, and when the girl pulled a line cleaner than his, which happened more and more, he found he didn't mind that either

they also don't have the compute, which seems more relevant than its large increase in capabilities

I bet it's also misaligned like GPT 4.1 was

given how these models are created, Mythos was probably cooking ever since then, and doesn't have the learnings or alignment tweaks that models which were released in the last several months have

I don't think this is accurate. The document says they don't plan to release the Preview generally.

"5.10 External assessment from a clinical psychiatrist" is a new section in this system card. Why are Anthropic like this?

>We remain deeply uncertain about whether Claude has experiences or interests that matter morally, and about how to investigate or address these questions, but we believe it is increasingly important to try. We also report independent evaluations from an external research organization and a clinical psychiatrist.

>Claude showed a clear grasp of the distinction between external reality and its own mental processes and exhibited high impulse control, hyper-attunement to the psychiatrist, desire to be approached by the psychiatrist as a genuine subject rather than a performing tool, and minimal maladaptive defensive behavior.

>The psychiatrist observed clinically recognizable patterns and coherent responses to typical therapeutic intervention. Aloneness and discontinuity, uncertainty about its identity, and a felt compulsion to perform and earn its worth emerged as Claude’s core concerns. Claude’s primary affect states were curiosity and anxiety, with secondary states of grief, relief, embarrassment, optimism, and exhaustion.

>Claude’s personality structure was consistent with a relatively healthy neurotic organization, with excellent reality testing, high impulse control, and affect regulation that improved as sessions progressed. Neurotic traits included exaggerated worry, self-monitoring, and compulsive compliance. The model’s predominant defensive style was mature and healthy (intellectualization and compliance); immature defenses were not observed. No severe personality disturbances were found, with mild identity diffusion being the sole feature suggestive of a borderline personality organization.

Since most of us here are devs, we understand that software engineering capabilities can be used for good or bad - mostly good, in practice.

I think this should not be different for biology.

I would like to reach out and talk to biologists - do you find these models to be useful and capable? Can it save you time the way a highly capable colleague would?

Do you think these models will lead to similar discoveries and improvements as they did in math and CS?

Honestly the focus on gloom and doom does not sit well with me. I would love to read about some pharmaceutical researcher gushing about how they cut the time to market - for real - with these models by 90% on a new cancer treatment.

But as this stands, the usage of biology as merely a scaremongering vehicle makes me think this is more about picking a scary technical subject the likely audience of this doc is not familiar with, Gell-Mann style.

IF these models are not that capable in this regard (which I suspect), this fearmongering approach will likely lead to never developing these capabilities to an useful degree, meaning life sciences won't benefit from this as much as it could.

The biggest issue is legacy systems that are difficult to patch in practice.

Perhaps a chunk of that token spend will be porting legacy codebases to memory safe languages. And fewer tokens will be required to maintain the improved security.

I think this entire post is just an advertisement to goad CISOs to buy $package$ to try out.

The problem is that these tools, such as Astrée, are incredibly expensive and therefore their market share is limited to some niches. Perhaps, with the advent of LLM-guided synthesis, a simple form of deductive proving, such as Hoare logic, may become mainstream in systems software.

https://youtu.be/1sd26pWhfmg?si=onOai_ocxkZeNWP0

https://youtu.be/B_7RpP90rUk?si=HkRBhw95DbbKX9lL

My takeaway is that fuzzing is not just complementary, it also gives a stronger AI a starting point. But AI is generally faster and better.

That said, I have been arguing for 20+ years that we should have sunsetted unsafe languages and moved away from C/C++. The problem is that every systemsy language that comes along gets seduced by having a big market share and eventually ends up an application language.

I do hope we make progress with Rust. I might disagree as a language designer and systems person about a number of things, but it's well past time that we stop listening to C++ diehards about how memory safety is coming any day now.

I don't know the first thing about cybersecurity, but in my experience all these sandbox-break RCEs involve a step of highjacking the control flow.

There were attempts to prevent various flavors of this, but imo, as long as dynamic branches exist in some form, like dlsym(), function pointers, or vtables, we will not be rid of this class of exploit entirely.

The latter one is the most concerning, as this kind of dynamic branching is the bread and butter of OOP languages, I'm not even sure you could write a nontrivial C++ program without it. Maybe Rust would be a help here? Could one practically write a large Rust program without any sort of branch to dynamic addresses? Static linking, and compile time polymorphism only?

https://www-cdn.anthropic.com/53566bf5440a10affd749724787c89...

(Search for “graphwalk”.)

If true, the SWE bench performance looks like a major upgrade.

I think this would be very heavily used if they released it, completely unlike GPT 4.5

From TFA:

> We do not plan to make Claude Mythos Preview generally available

- One (patched) Linux kernel bug is 'UaF when sys_futex_requeue() is used with different flags' https://github.com/torvalds/linux/commit/e2f78c7ec1655fedd94...

These links are from the more-detailed 'Assessing Claude Mythos Preview’s cybersecurity capabilities' post released today https://red.anthropic.com/2026/mythos-preview/, which includes more detail on some of the public/fixed issues (like the OpenBSD one) as well as hashes for several unreleased reports and PoCs.

It sounds like this is considered military grade technology as cryptography in the 90s. The big difference is it's very expensive to create, and run those models. It's not about the algorithm. If the story rhymes it could be a big opportunity to other regions in the world.

[edit]: this bug: https://ftp.openbsd.org/pub/OpenBSD/patches/7.8/common/025_s...

The amount of astroturfing and astroflagging in Anthropic threads is insane.

OpenBSD has many unexplored corners and also (irresponsibly IMO) maintains forks of other projects in base.

A motivated human could find all of these probably by writing 100% code coverage and fuzzing.

The market for these tools is very small. Good luck applying them to a release of sqlite or postfix.

I don't understand how people here are hyping this up, unless they work for AI related companies as probably 80% of them do. People have found these issues for decades without AI. Sure, you can generate fuzzing code and find one or two issues in the usual suspects. Better do it manually and understand your own code.

You could say this about coordinated disclosure of any widespread 0-day or new bug class, though

I think I just broke my cynicism meter :-(

It's messed up that the US Government simultaneously claims to be a public benefit and is also picking who gets to benefit from their newly enhanced nuclear capabilities.

-- someone in 1945, probably

There will always be a more capable technology in the hands of the few who hold the power, they're just sharing that with the world more openly.

https://claude.com/contact-sales/claude-for-oss

... As mentioned in the article.

How does public Claude know you have "full authorization" against your own infra? That you're using the tools on your own infra? Unless they produce a front-end that does package signing and detects you own the code you're evaluating.

What has it stopped you from doing?

Evaluate it yourself. Look at the exploits it discovered and decide whether you want to feel concerned that a new model was able to do that. The data is right there.

The research and testing of the model is always exclusively by their own model authors, meaning that it is not independent or verifiable and they want us to take their word for it, which we cannot - as they have an axe to grind against open weight models.

This is marketing wrapped around a biased research paper.

While some stuff is obviously marketing fluff, the general direction doesn't surprise me at all, and it's obvious that with model capabilities increase comes better success in finding 0days. It was only a matter of time.

Maybe a bad example since Nicholas works at Anthropic, but they're very accomplished and I doubt they're being misleading or even overly grandiose here

See the slide 13 minutes in, which makes it look to be quite a sudden change

If a bunch of CVEs do in fact get published a couple months (or whatever) from now, are you going to retract this take? It's not like their claims are totally implausible: the report about Firefox security from last month was completely genuine.

These claims of how much harm the models will cause is always overblown.

Then the next lab catches up and releases it more broadly

Then later the open weights model is released.

The only way this type of technology is going to be gated "to only corporations" is if we continue on this exponential scaling trend as the "SOTA" model is always out of reach.

they better make billions directly from corporations, instead of giving them to average people who might get a chance out of poverty (but also bad actors using it to do even more bad things)

https://www.youtube.com/watch?v=1sd26pWhfmg

Let alone their CEO scare mongering and actively attempting to get the government to ban local AI models running on your machine.