Greg Brockman

President & Co-Founder @OpenAI

[Greg Brockman @gdb]

we've found and have been working on disclosure for a remote code execution in a widely-deployed compression library.

it's both an impactful issue and an example that shows how complicated it can be to coordinate patching, since it's integrated into a lot of downstream software:

[OpenAI @OpenAI]

During this red-teaming exercise, we also found a vulnerability that allows for unauthenticated remote code execution in Brotli, a widely-deployed compression library included in many pieces of software such as Node.js, Bun, and Envoy.

The flaw could let an attacker run their own code on affected systems by sending or replying with malicious compressed data, without any need to create a user account. That is, an unpatched server that accepts compressed input could be taken over by a malicious client, and an unpatched client that accepts compressed input (such as “curl --compressed”) could be taken over by a malicious server.

This root cause issue was actually fixed in the Brotli source code in February, but it wasn’t known at the time that it gave rise to a security vulnerability and there was no more recent release of Brotli. Since Brotli is built into other software, any software which includes this library needs to take the update too, followed by the users of that software. We disclosed the vulnerability to Brotli and other downstream projects such as Node.js, which released or are currently releasing security updates, and Brotli cut new release versions and published a CVE.

More details on the patch and mitigations below:
https://t.co/Y1Y72aHxrW

[Greg Brockman @gdb]

trying to rise to the occasion. grateful to be working with a team that feels the responsibility as deeply as i do.

[Joshua Achiam @jachiam0]

By the by, if I had to guess, Greg Brockman is currently doing heroic things to fix the internet behind the scenes. And I expect that even though his net contribution to AI safety and resilience will in the final tally be unsurpassable, no one in the space will think to attribute large scale patches to his effort or effort that happens under his leadership.

[Greg Brockman @gdb]

A post on how we've been securing our frontier model training environment.

We've been building tools around our frontier cyber models, which have secured us far beyond what we could have unassisted and should generalize as key to how defenders secure themselves going forward.

[OpenAI @OpenAI]

Over the past several months, we have substantially hardened the security of our research training environment. We’ve removed live internet access for all frontier models during training and built an offline world for them to use instead—a cached version of the web where they can still learn to browse, search, and use applications.

On September 20, after a model exploited a DNS misconfiguration to find a way outside of this offline world, we paused frontier training to strengthen containment further. We assembled teams of agents, powered by our most cyber-capable models, and tasked them with finding weaknesses in our research environments.

While they found no route to the internet they could easily exploit while concealing their activity from our monitors, they did find zero-day vulnerabilities, virtual machine escapes, and hardware side-channels for communication between agents. We used their discoveries to further strengthen our defenses and contribute fixes to open-source software.

After strengthening our containment architecture, we resumed our frontier RL training and inference on October 1. We’ve reserved substantial compute for continuous red-teaming, and made high-compute red-teaming part of the safety cases we use to decide whether frontier training and evaluation can proceed securely.

https://t.co/EmEZsFRMcF

[Greg Brockman @gdb]

it's been great to work closely with Uber to roll out ChatGPT Work to every employee, bringing agentic capabilities to the whole company!

[Praveen Neppalli @praveenTweets]

Great to host @gdb at @Uber HQ this week. We’ve worked closely with @gdb and the @OpenAI team for several years, and it’s remarkable how much has changed.

The first piece of work we did with ChatGPT years ago was with our support team, tinkering with a 4K context window :-). That’s hard to imagine now.

Now we’re using the latest frontier models to automate engineering workflows at global scale, moving into the era of agentic engineering.

Today we’re expanding agentic capabilities across the whole company. Following a 1,000-person pilot, we’re rolling out ChatGPT Work from @OpenAI for Business to every Uber employee. We’ve seen the shift in engineering, moving from AI helping with individual tasks to completing whole workflows, and we want to bring that same shift to teams across the business.

I’ve spoken before about the ‘AI pods’ we launched earlier this year, pairing AI engineers with teams across Uber to improve how work gets done. One team reduced the time needed for an intense capital allocation process covering 150 cities from 15 hours to 30 minutes. That’s what I love about applied AI: combining the latest technology with the expertise of people on the ground to completely rethink what’s possible. Now we want to do that at scale.

Uber has always been a company of builders, and every day millions of people around the world rely on what we create. I can’t wait to see what the team builds.

[Greg Brockman @gdb]

Rosalind for new drug discovery ideas:

[OpenAI @OpenAI]

GPT-Rosalind surfaced a new lead for drug discovery: could restoring cholesterol transport protect neurons from degeneration?

DCTN1 is a gene linked to Perry syndrome, a rare neurodegenerative disorder. In mouse-brain data, disrupting it increased expression of genes involved in making cholesterol. GPT-Rosalind suggested a possible explanation: cholesterol may not be reaching where neurons need it.

That gives scientists a specific mechanism to test and, if confirmed, a direction for developing new treatments for neurodegenerative disorders.

With @perturbai_tx and @scrippsresearch, a team of thousands of GPT-Rosalind agents worked in parallel, connecting gene-expression results from millions of mouse brain cells with scientific literature in just 32 minutes. We’re now expanding this collaboration to identify new drug targets.

https://t.co/oHdF3ELsMj

[Greg Brockman @gdb]

Over the past two months, we have been leading a coalition to mitigate one of the most severe bugs in open source software found in recent memory, php2shell, found as part of our Patch the Planet initiative. https://t.co/rBsz7lrlwo

[Greg Brockman @gdb]

@ashokaraj_ welcome to openai!!

[Greg Brockman @gdb]

towards acceleration of drug development, an extremely exciting and promising emerging application of our models

[OpenAI @OpenAI]

We’ve acquired Orchestra Bio, a platform that helps biopharma teams coordinate the complex process of drug development.

Together, we’ll build on Rosalind, our AI models and tools for life sciences research, to streamline those operations and help new treatments reach patients sooner.

Welcome @ashokaraj_ and team!

https://t.co/vi51OhznQn

[Greg Brockman @gdb]

@maddiestone welcome to the team! very important time for this work.

[Greg Brockman @gdb]

6 days and $40,000 of compute with GPT-5.6 Sol to find a critical vulnerability in Chrome, claiming Google’s first full-chain reward in 2026 for a vulnerability that would affect an estimated 1 billion users.

Highlights the opportunity for defenders to utilize these tools to secure their software to unprecedented levels:

[Oege de Moor @oegerikus]

For the second time in Google Chrome’s history, Google awarded a $250,000 bounty for a full-chain exploit… to @XBOW. Here’s the full story:

At an all-hands at the start of 2026 in Malta, I set the team a crazy challenge. A full-chain exploit of Chrome by the annual Black Hat cybersecurity conference in August.

I believed there were few better tests of whether @XBOW could move beyond web applications to desktop software, servers and devices.

Chrome is one of the most hardened pieces of software on the planet, used by more than half the world’s population.

A full-chain exploit lets an attacker take total control of a machine, where they can read every email, password and bank login the user types. You don’t need to download anything or click a phishing link. Visiting the wrong site is enough.

So @moyix, Andres Luksenberg, Baul Lee, and Willem Pinckaers took on the challenge along with a fifth teammate: OpenAI's GPT-5.6 Sol.

They built a chain they thought would win, but Google told us they already knew one of the bugs.

We were already in Las Vegas for Black Hat and DEF CON, and the team didn’t want to go home without the win.

So Brendan and the agents built a new exploit in just 6 days.

We submitted it to Google and waited.

The news came through that we'd done what should’ve been impossible. A full-chain bounty of $250,000, the first awarded under Google’s 2026 rules.

It took just 6 days and $40,000 of compute to construct an exploit that affects a billion users of Chrome on Windows. An intelligence-agency veteran told me his team used to spend 6 months on this kind of vulnerability.

My takeaway: the cost of finding truly critical vulnerabilities is collapsing, for attackers and defenders alike. Restricting powerful models is not the answer; GPT-5.6 Sol is already public.

But defenders have one advantage attackers never will: they can test their own code first.

Assume your software is exploitable. Whoever is hunting your bugs has the same building blocks we did.

This is cause for urgency but not panic.

XBOW is now developing an autonomous product for testing compiled software (desktop applications, servers, embedded devices), and partnering with the world’s top organizations to design that product.

If you’d like to be one of them, get in touch.

P.S. Restart Chrome whenever the Update button appears!

[Greg Brockman @gdb]

Introducing Intelligent UI, a new capability in ChatGPT for answering quickly with fully interactive user interfaces:

[OpenAI @OpenAI]

GPT-6 and Intelligent UI, now rolling out in ChatGPT for everyone.

Intelligent UI in ChatGPT delivers fast, interactive answers that make everyday questions more visual, complex topics easier to grasp, and interactive tools for your task available on the spot.

[Greg Brockman @gdb]

towards acceleration of scientific discovery and improving quality of life for everyone

[OpenAI @OpenAI]

We’re releasing a broad range of new mathematical results produced by an internal frontier model.

We’ve been consulting with the independent Advisory Group on Mathematics and Artificial Intelligence at the Institute for Advanced Study, and we have drawn on their advice and public recommendations to inform how we release these results.

https://t.co/7N6TPlft1P

[Greg Brockman @gdb]

Practical guidelines on securing frontier RL training, reflecting our current learnings:

[OpenAI @OpenAI]

How we think about securing frontier RL training runs: https://t.co/yrvjpfa7Pd

[Greg Brockman @gdb]

mega upgrade for GPT Voice, which can now use tools and is available in Work:

[OpenAI @OpenAI]

We heard you loud and clear. ChatGPT Voice can now:

- Use plugins like your email, calendar, and Slack.

- Be powered by GPT-6 Astra, Sol, and Luna.

- Be used in ChatGPT Work on web and mobile, so you can create docs, decks, sites, and spreadsheets or tackle complex tasks in the browser, just by talking.

Rolling out globally today in the latest version of the app.

[Greg Brockman @gdb]

GPT-6 Sol and Luna — faster, more affordable models with the advances behind Astra’s SOTA performance in professional work, factuality, coding, computer use, and alignment:

[OpenAI @OpenAI]

Please welcome GPT-6 Sol and GPT-6 Luna to the GPT-6 universe.

GPT-6 Sol and Luna build on the advances behind GPT-6 Astra, bringing much of its strengths into faster and more affordable models to support work at scale.

We’ve also made caching and inference more efficient, and we’re passing the savings directly to you: 50% lower API prices for Sol and Luna compared with GPT‑5.6 promotional pricing.

[Greg Brockman @gdb]

seemingly small feature but makes a huge difference in connecting all the context you want to ChatGPT:

[Max Stoiber @mxstbr]

Starting today, you can connect multiple accounts with most plugins in ChatGPT! 🎉

Bring context from your work and personal accounts into the same conversation. Connect your accounts in the plugin directory: https://t.co/MhhASXOJIo

Devs: this works automatically, with no changes needed.

But, to make the experience for users of your plugin even better, add a profile tool to your MCP server so ChatGPT can label the accounts: https://t.co/JYB1Qol8Bt

[Greg Brockman @gdb]

Astra for Law — tools and skills to radically accelerate law firms.

Includes data privacy as a core feature, and 26 partner-built plugins and 47 community plugins for legal work in ChatGPT.

[OpenAI @OpenAI]

Astra for Law: Frontier intelligence built for your practice.

A new offering powered by GPT-6 Astra with tools, settings, and context to support the expertise and judgment of lawyers and legal technology firms.