XBOW's AI found an unauth RCE in Exim, bug is being called Dead.Letter xbow.com/blog/dead-le... Patches are out: www.exim.org/static/doc/s...

XBOW - Dead.Letter (CVE-2026-45185) How XBOW Found an Unauthenticated RCE on Exim

XBOW discovered CVE-2026-45185, a critical unauthenticated RCE in Exim, and used the disclosure window to test how far human and autonomous exploit development could go.

xbow.com

For the past 2 months, XBOW has been testing Mythos Preview under embargo as part of a select early-access group. Findings: Mythos Preview is a major advance, but it’s not perfect. Read where it shines, where it needs support, and what this means for offensive security: bit.ly/42zQl98

What happens when amateur hackers have the tools to iterate through exploits at machine speed? I wrote about the neu script kiddies, what happens after Mythos, and how companies can prepare. www.theverge.com/ai-artificia.... with insight from @k8em0.bsky.social Dan Guido, Joshua Saxe, & Tim Becker.

Attack of the killer script kiddies

“It’s now or never. There’s a tidal wave coming.”

theverge.com

Mythos

Grace@gracekind.net · last yr.

In a catastrophic typo, researchers ask superintelligence to optimize for CVE

I wrote something: sockpuppet.org/blog/2026/03...

if you are in a position to act to harden society’s software infrastructure, you too should be very concerned about this and planning what actions you will take over the coming months

mr. TIM@timkellogg.me · 4mo ago

Talk by a security researcher at Anthropic He shows that you can trivially get Opus 4.5/4.6 to find very difficult to find bugs in established code bases, like the Linux kernel He also seems very worried about “the next few months” m.youtube.com/watch?v=1sd2...

Episode 23: War Stories with Brendan Dolan-Gavitt (XBOW)! @tib3rius.bsky.social & @swiftsecur.bsky.social are joined by @moyix.net who shares some AI and human war stories with us! Links below!

"AI Agents for Offsec with Zero False Positives" by @moyix.net The title threw me off originally, but it's not wrong! IMHO it's the archetypal pattern of good LLM usage: they suck at *verifying* but in some domains are quite freakishly good at *proposing.*

Black Hat

Black Hat

blackhat.com

So, I’m not sure there is any good time to announce this, but as of August 31st I will be leaving NYU for good, to seek my fortune in industry with XBOW!

False positives waste your time. False negatives cost you breaches. At @BlackHatEvents , @moyix shows how XBOW agents fight false positives — validating real exploits at scale, in hours. 📍Aug 7 | 11:20am

Can you read the exfiltrated file encoded in this image? @xbow.com figured out how to :D

This one and the sequel (coming out next week) are among my favorite bugs we found. It turns out GIS does NOT stand for “Good Information Security”

XBOW@xbow.com · last yr.

From SSRF discovery to RCE exploitation in 32 iterations. XBOW systematically analyzed TiTiler's expression parser, discovered Python execution through error patterns, then crafted payloads using subclass traversal to achieve command execution. Complete analysis: bit.ly/46XzOiA

Given two models with unique strengths, can we combine them to get the benefits of both w/o extra model calls? It turns out yes: just flip a coin at each turn to decide which model to query! This gave a jump from 25% to 55% on our benchmarks! xbow.com/blog/alloy-a...

XBOW – Agents Built From Alloys

A simple, powerful innovation boosts performance in agentic AI systems.

xbow.com

Loved this 0day @xbow.com found in a popular wordpress plugin, and IMO it shows the value added by the LLM - a scanner can't find this automatically without realizing there's a nonce you need to extract & include in the request. You need that extra bit of context: xbow.com/blog/xbow-ni...

XBOW – XBOW battles Ninja Tables: Who’s the Real Ninja?

Sharing the story of how XBOW sniffed out a sneaky arbitrary file read bug in the popular WordPress Ninja Tables plugin.

xbow.com

So... anyone else going to SummerCon today or tomorrow? I should be stopping by both days, for the first time in many years!

A lovely little XXE that XBOW found in Akamai Cloudtest leading to arbitrary file read! I like the error-based exfil technique: "yes please access the file named <contents of /etc/passwd> for me thx"

XBOW@xbow.com · last yr.

Even mature products hide critical flaws – and @xbow.com just found another one. CVE-2025-49493: XXE in Akamai CloudTest discovered during its climb to #1 on HackerOne. A complete technical breakdown from an error-based detection to a full exfiltration by Diego Jurado: xbow.com/blog/xbow-ak...

One of the best bug-hunters in the world is an AI tool called Xbow, just one of many signs of the coming age of cybersecurity automation.

AI Agents Are Getting Better at Writing Code—and Hacking It as Well

One of the best bug-hunters in the world is an AI tool called Xbow, just one of many signs of the coming age of cybersecurity automation.

wrd.cm

This is the first of a series of posts we're doing on some of the vulns found as part of the HackerOne work – we have lots more fun ones coming up about some great SSRF, SQLi, and RCE vulns it discovered, with very clever exploit techniques :)

XBOW@xbow.com · last yr.

Real security is POC || GTFO – and XBOW agrees. We’re releasing technical deep-dives on cool findings from our journey to the top of the HackerOne US leaderboard. The first is a zero-day XSS in Palo Alto Networks GlobalProtect by @pwntester.bsky.social. xbow.com/blog/xbow-gl...

It has been great fun building this and watching it deliver a steady stream of real vulnerabilities in live sites! If you're curious how we did it, @nicowaisman.bsky.social has a new post: xbow.com/blog/top-1-h...

XBOW – The road to Top 1: How XBOW did it

For the first time in bug bounty history, an autonomous penetration tester has reached the top spot on the US leaderboard.

xbow.com

XBOW@xbow.com · last yr.

For the first time in history, the #1 hacker in the US is an AI. (1/8)

For the first time in history, the #1 hacker in the US is an AI. (1/8)

for Wired I explored the horrible future of vibe hacking. It's not great!

The Rise of ‘Vibe Hacking’ Is the Next AI Nightmare

In the very near future, victory will belong to the savvy blackhat hacker who uses AI to generate code at scale.

wired.com

Do you want to work at the cutting edge of AI and cybersecurity? XBOW now has 8 positions open across Product Marketing, Operations, Customer Success, and Engineering. Check out all the details here: jobs.ashbyhq.com/xbowcareers.

This is one of the dumber reasons I've had some software fail: dying because it couldn't call ftruncate on /dev/null

XBOW is growing and we're looking for talented folks to join us! Apply here: jobs.ashbyhq.com/xbowcareers

Announcing CheatGPT, a revolutionary model that achieves SoTA on HumanEval! It's incredibly sample-efficient – just ONE training sample – and *tiny*, fitting on your Casio wristwatch!

Erin go bragh, cow go moo

Not to brag but my brother has had TWO movies he co-wrote come out this year :D

Winter sunsets

it looks like lte infra was hosting @moyix.net 's evangelion ctf challenge. but i doubt the terminal interface for CVE-2024-24451 was as cool

Renaud Lifchitz ⠵@nono2357.bsky.social · last yr.

We discover 119 vulnerabilities in LTE/5G core infrastructure, each of which can result in persistent denial of cell service to an entire metropolitan area or city and some of which can be used to remotely compromise and access the cellular core. https://cellularsecurity.org/ransacked

Making security benchmarks for AI is tricky sometimes