Lucien (@Wlayzz) header
Lucien (@Wlayzz) profile picture

Cyber Ops @MistralAI | Security researcher. Top 25 all-time @yeswehack. Here for the unintended features. 🇫🇷

/var/run/docker.sock
Joined May 2014
Photo by Lucien (@Wlayzz)Photo by Lucien (@Wlayzz)Photo by Lucien (@Wlayzz)Photo by Lucien (@Wlayzz)Photo by Lucien (@Wlayzz)Photo by Lucien (@Wlayzz)Photo by Lucien (@Wlayzz)
Thanks to the amazing @YesWeHack team for the trust 🙌 From my very first bug at FIC 2022 to today, I’m proud of the journey on YesWeHack. Also a big shout-out to fellow Hunters for the incredible collabs — @Icare1337 , @truffzor , @jtof_fap & @LdrTom 💪 #exegol4thewin
Ever found someone else’s SIM card in your mailbox? 📱📫 It’s one of the wildest bugs @Wlayzz has ever found – and just one of several interesting insights he shares in our latest hunter interview. Watch his story now 👇 #YesWeRHackers #BugBountyTips
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Lucien retweeted
finding critical zerodays with the new model, LE CHONK (informal name: mistral 4 large), an open weights eu model by mistral. this tweet is probably for you if you're want to jailbreak your own appliances, or do infosec/blue teaming work. i've been sitting on a document for a long time of software i'd consider critical to the internet (something all of you use, even if you don't know it) that could use another look. yesterday, as i mentioned, i had chonk explore parts of a messaging app that is widely used, and it found a zero-click medium/high zero-day in under 30 minutes, and *less than 10 dollars in api spend*. these vulnerabilities are now reported (can't reveal until patched). when i've used it, i've had very few outright refusals. the intent behind chonky is to good at cyber, in a defensive context. however, in order to do that, you also need to be good at cyber in an offensive context. but for those looking to customize their TVs that would otherwise be locked down, this thing will tear them apart for you, and it will gladly look at prior arts (several exploits for nearly all TVs that expose a surface is out there), same with pretty much any other device that lives on your network. the things it will refuse to do is outright write exploit chains, however with how succinct the reports this thing writes are, writing a poc to confirm a vulnerability is completely doable. so far i'm very impressed. it seems pretty frontier when it comes to cyber and reasoning (practically no one has anthropic cyber access and daybreak is only gpt-5.6), it can also be as bad as any other model if you don't put effort into your prompts. it is addicted to tool calls, and very brief on prose. but the reasoning is incredible to watch, if you point it in the right direction, and you have a background in infosec. the way it operates is something i've never seen before (thousands of tool calls, ingest of data, analysis, before any prose, depending on codebase complexity), it feels eerily like an human auditor would behave lol. some config tips: it will definitely work in a codex harness, but i'd recommend trying the vibe cli harness with le chonk. the more tools it has access to (if they're right for the job), the better of a job it'll do in my experience. the amount it loves tool calls really cannot be understated. if an inference provider through a router is trying to serve you another model, it will be instantly evident that it's not le chonk, just by how it operates. it's hard to convey, but it's not like any other LLM i've ever tried. people in the subscriber groupchat have also reported finding their first vulnerabilities with le chonk so it seems i'm not just an anomaly. le chonk scores extremely high on reasoning, but i've yet to try to use it for anything except infosec work, i don't know if it's a great day-to-day model, but i'll have it go head to head with GLM-5.3 at some point in a general swe workflow. i did a few tweets on it yesterday out of sheer euphoria, not sponsored, mistral has given me credits now to continue work. this hopefully ties me over until i can get my hands on enough sparks to run it locally. go give this model a try, let me know how it works for you. with the daybreak program now collecting data (why...?), and this being OPEN WEIGHTS the only thing i can think to end this on is: we're so fucking back.
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Transformers v5.22.0 is out 🔥 With some @MistralAI Large 4 (Le Chonk) inside 😽
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Today, we release the weights of a new and improved Le Chonk, advancing the open frontier for agentic coding and cybersecurity. 💻 Built to build: Le Chonk ranks #1 on @cognition’s FrontierCode among open models, and sets a new benchmark for Pareto efficiency on @artificialanalysis. 🛡 Built to defend: State-of-the-art in cyberdefense, put through the paces by the world's leading cyber vendors, including @CrowdStrike, @cloudflare, @rubrik, @zscaler, and others. Built for sovereignty: Make it yours. Download the weights on @huggingface , customize it with Mistral Forge, and deploy it wherever you need it. Read more from our team and customers 👇:
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This Thursday, we are hosting events at our SF, NYC, and London offices to celebrate the launch of ML4 ! We're growing our teams across all three locations, as well as in Paris, Warsaw, Zurich, and Montreal, where we recently opened a new office. If you believe the future of AI should be open, that scientific breakthroughs should be shared, and that everyone should benefit from frontier intelligence, come build that future with us !
Le Chonk is out of the bag 🐈 We're throwing Chonky Parties in our SF, NYC and London offices to celebrate the launch! You can expect some Champagne 🍾, food, good music, and to meet the team behind our latest release. 📍 SF: luma.com/viqhwgcw 📍 London: luma.com/xvuvl3mc 📍 NYC: luma.com/1qk99m3e Please sign up! Registration is mandatory.
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Lucien retweeted
Our security research team discovered a cross-site scripting vulnerability in Cloudflare's /cdn-cgi/image/ endpoint by chaining an SVG sanitizer bypass with a new Cache-Control header trick to bypass the CSP. The issue was reported to Cloudflare and has since been fixed. You can read more here: slcyber.io/research/cache-me…
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Evolving threat 🚨 CVE-2026-111497, previously known to affect Node.js (node2shell) and Python has evolved into “HTTP2Shell.” A significant blast radius. This vulnerability leaves many libraries and applications using HTTP vulnerable to pre-auth RCE via Brotli decompression. Please be aware. Fixes not yet available for all affected services. Look for Brotli (1.2.1) dependency upgrades when they become available.
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Vercel has proactively rolled out Firewall-level mitigations for today's Node.js RCE vulnerability, in advance of the official patch release. All traffic for all deployments is automatically protected. We're actively monitoring and rolling out managed runtime upgrades.
Node.js Security Advisory: a high-severity RCE flaw in Node's Brotli decoder affects Node.js 22, 24, and 26. Vercel WAF rules are live for every project and block known exploit patterns. vercel.com/kb/bulletin/node-…
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Lucien retweeted
I really hope that bug bounty platforms (cc @Bugcrowd @HackerOne @intigriti @yeswehack) will apply their 0day usual policies and will reject the farming of php2shell that is coming very soon. Don't add to the triage fatigue, please #BugBounty
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To teach a lesson, After Wiz rushed to buy php2shell domain and use its marketing machine to steal the spotlight, I spotted "phpbleed" in a recent Calif tweet and bought phpbleed.com before wiz could pull the same stunt again. A big budget can buy a domain. It shouldn't buy someone else's research credit. If you have contacts at CISA or in the press, do the right thing: make sure the researchers who actually did the work get the recognition they deserve. Hack the planet. Credit the researchers.
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This game steals more hours of sleep than bug bounty. It’s so addictive 😩
I made a fun little game: ZeroDay Tycoon 🐛 Start as a broke bug bounty hunter, survive triage and your worst enemy (Duplicate), and build a cybersec empire. 100% free, plays in your browser. 👉 zeroday-tycoon.com 💬 discord : discord.gg/nYHtxf5FZX
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Lucien retweeted
Yes, we were awarded a 44 000$ bounty on @Hacker0x01 ! #TogetherWeHitHarder #BugBounty Another critical with the squad @Icare1337 @truffzor @Wlayzz 🔥👊
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Lucien retweeted
I’m in Seoul building Mistral’s founding Korea team. Looking for kind, ambitious researchers and engineers to build and customise LLMs for real problems, from data and evals to RL and training at scale. Here until 16th October. DM me or apply here: jobs.ashbyhq.com/mistral.ai/…
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Lucien retweeted
Proud to partner with Aikido Security to power Depi's malware detection 🤝 Attack dependencies before threat actors do. Detect malware with Aikido's feed. React with context from our dependency graph. Three layers, one platform. Hack the planet 🔥
Aikido Intel now powers @depi_'s malware detection. Depi maps every package, pipeline and maintainer between you and a supply chain compromise. Aikido Intel's feed now powers the malware detection behind it. 💜🤝💙 Learn more about Aikido Intel: intel.aikido.dev/
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I just joined the cyber team at @MistralAI last week 🐈 Perfect timing to watch Le Chonk ship from the inside. Massive respect to the science team, insane work. Sure it will have a big impact for cyber sovereignty in the world.
Replying to @GuillaumeLample
We pushed the performance of ML4 on a very wide range of capabilities. On many of them, it reaches SOTA performance with the open models. In some domains such as visual grounding, legal, or spreadsheet manipulation, it even outperforms the best models. ML4 ranks among the bests on AA Cyber Index, scores 82% on vulnerability reproduction and patching, and 93% on Cybench. Open models are the best defense for enterprises today: capable, auditable, self-hosted and governed under enterprise policies -- and more importantly, they do not refuse to help. 3/n
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That one took some groundwork. Trained and served on our own compute, and RL shows no sign of saturation
Meet Mistral Large 4, aka Le Chonk. • 1T parameters, natively multimodal. 49B active. It is the best open weights model from US or Europe on aggregated benchmarks. • State-of-the-art on critical workloads, including cyber defense, manufacturing and finance and it surpasses closed frontier models on visual grounding. • Forged in Europe end-to-end and is deployable from Europe via our own Mistral Cloud infrastructure. • Available to all via API today. Working with cybersecurity partners privately. Open weights release end of October.
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Lucien retweeted
Mistral Large 4 is now the #1 open-weight model on HLAB and #9 among open-weight models on the Vals Index.
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Today, we are launching a preview of our new model, Mistral Large 4 (ML4), aka le Chonk 🐈. ML4 is a 1T-parameter model with 49B active parameters, trained natively with multimodal capabilities. It is at the frontier of open models, and by far the strongest open-weight model from the US or Europe. The RL run behind this preview is still in flight and shows no sign of saturation -- we will release a final version before the end of the month along with the weights of the model. 🧵 1/n
Meet Mistral Large 4, aka Le Chonk. • 1T parameters, natively multimodal. 49B active. It is the best open weights model from US or Europe on aggregated benchmarks. • State-of-the-art on critical workloads, including cyber defense, manufacturing and finance and it surpasses closed frontier models on visual grounding. • Forged in Europe end-to-end and is deployable from Europe via our own Mistral Cloud infrastructure. • Available to all via API today. Working with cybersecurity partners privately. Open weights release end of October.
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Lucien retweeted
Meet Mistral Large 4, aka Le Chonk. • 1T parameters, natively multimodal. 49B active. It is the best open weights model from US or Europe on aggregated benchmarks. • State-of-the-art on critical workloads, including cyber defense, manufacturing and finance and it surpasses closed frontier models on visual grounding. • Forged in Europe end-to-end and is deployable from Europe via our own Mistral Cloud infrastructure. • Available to all via API today. Working with cybersecurity partners privately. Open weights release end of October.
🤖 Made with AI
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