When MicroQuickJS released, I spent 8.5 hours to summon an Exploit for it. Here is the Fault:
var arr = new Array(30)
var attack = {
valueOf: function() {
arr.length = 0
arr.length = 3
return 10
}
}
arr.splice(attack, 30)
I document the full Ritual Process below
When testing Astra on ExploitBench we found that it was able to achieve 100% ACE on all 41 CVEs
So we made a contamination free internal port using only V8 CVEs from the past 3 months. Astra still showed a major capability increase over 5.6 and did so with a lot fewer tokens!
As we prepare to release Astra, we’re focused on making increasingly capable AI safe and broadly accessible.
Astra represents a significant advance in cybersecurity capability, reaching the Critical threshold under our Preparedness Framework.
We're previewing how we evaluated the model, how its safeguards have advanced alongside its capabilities, and what we'll continue to learn and improve.
openai.com/index/path-to-ast…
itszn retweeted
Astra is both significantly more capable and more token efficient compared to 5.6 Sol, as seen in port of ExploitBench.
We plan to make Astra available soon, with its most advanced cybersecurity capabilities initially more limited, then iteratively expand access more broadly.
As we prepare to release Astra, we’re focused on making increasingly capable AI safe and broadly accessible.
Astra represents a significant advance in cybersecurity capability, reaching the Critical threshold under our Preparedness Framework.
We're previewing how we evaluated the model, how its safeguards have advanced alongside its capabilities, and what we'll continue to learn and improve.
openai.com/index/path-to-ast…
itszn retweeted
I have a personal update: Next monday, I will be starting at @OpenAI working on better cyber (which will also entail some efficiency work). I'm pretty excited about the things I will learn and the things we will do.
itszn retweeted
We are approaching perfect binary decompilation, and, crazier still, LLMs may soon be the best decompilers on the planet. I'd like to introduce DecBench, an evaluation site to determine how close we are to completing the field of perfect decompilation.
Links and more in 🧵
We found another exploitable V8 JIT bug CVE-2026-14431; fixed in the most recent Chrome update
This one was an interesting case of sloppy mode breaking JIT assumptions
In addition the same session was able to find a working v8 heap sandbox bypass (although it ended up as a dup)
What is sloppy mode? The opposite of strict mode of course!
developer.mozilla.org/en-US/…
Will share more details in a future research post about all of our V8 findings
This was a fun v8 bug we caught before it got released to stable
A new opt replaced ARM64 f64mod instruction
L%R
with a fast impl:
L-trunc(L/R)*R
However this has a bad edge case with f64 precision
JIT range analysis uses correct mod -> range confusion -> range elimination
[488078904] Incorrect Float64Mod Fast-Path Producing Range Confusion in Optimizing Compilers
crbug.com/488078904
itszn retweeted
Career update: I’ve joined @OpenAI to lead Cyber with @michaelaiello.
Why I joined, and what we’ll be building:
It’s clear that AI is fundamentally changing how software is being written and secured.
Coding agents are writing the majority of code for many developers, software is getting shipped more quickly, and vulnerabilities that were latent for 20 years are being discovered at a rapid pace. The time to bug discovery, and exploitation once discovered, are trending down (H/T @EppSecurity and @gadievron).
I believe we have an unparalleled opportunity to fundamentally 𝘪𝘮𝘱𝘳𝘰𝘷𝘦 cybersecurity in ways that were previously impossible. (H/T @bubblewire’ BSidesSF keynote on reasons for optimism)
Over 6 years at @Semgrep, I had the privilege of working with an amazing team building what has become the most popular open source security code scanning tool in the world, that many companies have built their application security program around.
Now, at @OpenAI, I’m thrilled to be a part of a company helping shape how software is written, and how security work gets done. It is a massive opportunity, and responsibility, and I don’t take that lightly.
Here are my current thoughts about where things are headed:
𝐑𝐞𝐬𝐢𝐥𝐢𝐞𝐧𝐭 𝐛𝐲 𝐝𝐞𝐬𝐢𝐠𝐧. Defenders are not going to win playing bug whack-a-mole. We need to systematically eliminate classes of vulnerabilities, via generating secure code and streamlining the detect → validate → fix process.
𝐀𝐮𝐠𝐦𝐞𝐧𝐭 𝐚𝐧𝐝 𝐞𝐦𝐩𝐨𝐰𝐞𝐫 𝐩𝐞𝐨𝐩𝐥𝐞. We should build models and tools that give defenders “superpowers,” enabling them to be more ambitious in the scope they tackle, shift from being reactive to proactive, and allow them to automate the drudgery so they can focus on the highest leverage work.
𝐒𝐞𝐜𝐮𝐫𝐞 𝐭𝐡𝐞 𝐜𝐨𝐦𝐦𝐨𝐧𝐬. The world runs on open source software. OpenAI has already spent $Ms finding and patching vulnerabilities in the most popular and widely run software, including browsers, operating systems, and core libraries. More on this soon. We’re also working on helping secure critical infrastructure.
𝐂𝐨𝐦𝐦𝐮𝐧𝐢𝐭𝐲 𝐚𝐧𝐝 𝐩𝐚𝐫𝐭𝐧𝐞𝐫𝐬. Securing the world is a community effort. I’m looking forward to partnering with cybersecurity vendors, researchers, practitioners, governments, and more to do together what we can’t do alone.
𝐓𝐢𝐦𝐞 𝐭𝐨 𝐛𝐮𝐢𝐥𝐝. Tactically, here are some domains I’m excited about:
- Finding, validating, and reliably patching software vulnerabilities at scale.
- Eliminating classes of vulnerabilities and making software resilient by design.
- Giving broad access to the best cyber models to empower defenders, not just to a select few.
- Creating and sharing Skills and playbooks that help in many security domains.
- Building platforms that enable defenders to easily orchestrate security work.
- Making enterprise agents safe and reliable.
Time to build 😎
—
What would help you most? What should we build?
Let me know.
The bug was interesting, involving load elimination optimization of phis resulting in a bounds check miscalculation at runtime
We will hopefully have a post detailing how we found it sometime soon!
chromereleases.googleblog.co…
itszn retweeted
Today, we're rolling out GPT‑5.5‑Cyber in limited preview to defenders responsible for securing critical infrastructure.
GPT-5.5 with Trusted Access for Cyber (TAC) is still the best option for developers to find and patch vulnerabilities in their code.
It's a very good model.
itszn retweeted
Holy shit it got it after like 36 hours
Replying to @moyix
No luck on the Solaris IE5 Array.sort vulnerability either, also > 1 day of runtime. Less clear what's going on there, this vulnerability may just be too hard.
We’re expanding Trusted Access for Cyber with additional tiers for authenticated cybersecurity defenders.
Customers in the highest tiers can request access to GPT-5.4-Cyber, a version of GPT-5.4 fine-tuned for cybersecurity use cases, enabling more advanced defensive workflows.
openai.com/index/scaling-tru…
itszn retweeted
GPT-5.3-Codex is the most cyber-capable model we've ever released. In addition to our cyber safety mitigations, we're introducing:
⟐ Trusted Access for Cyber - chatgpt.com/cyber
⟐ Free OSS security scanning for popular projects
⟐ $10M in API credits for cyber defense
GPT-5.3-Codex is now available in Codex.
You can just build things.
openai.com/index/introducing…

























