On November 10, 2026, Ars Technica reported that more than 35,000 web apps made with xAI’s Grok Build were open to anyone who had the link. The finding comes from security firm Claroc: of the 37,571 Grok Build apps still online when it tried them, 35,578 (94.7%) opened with no sign-in. If you’ve used Grok Build for anything with real names, numbers, or passwords in it, check it today. Treat anything you published as public until you’ve confirmed otherwise.
What Happened: 35,000 Grok Build Apps Left Open
Grok Build is xAI’s AI app builder. The product is in beta, and its model slug is grok-build-0.1 in the release notes. You describe an app in plain English, like “a sales dashboard for my team.” Grok Build writes it, and you can publish it to share with others. Each app gets its own randomized web address under the grok.me domain.
Security firm Claroc published the research, including its method, counts and access settings, in Claroc’s report. Many of the open apps were never meant to be public. Confirmed examples included an ICU patient’s lab results, a hospital group’s staff list, business and sales plans, advertising proposals, and a cruise ship’s galley checklist. One contractor’s timesheet app held 18 employee accounts with plain-text passwords in its code (MLQ and Data Phoenix also covered it: MLQ, Data Phoenix).
The links were random, so nobody had to guess them. That didn’t help. Passive DNS services logged them anyway. Think of passive DNS as a giant phone book that quietly writes down the addresses computers look up. Claroc says anyone with an account on such a service can search it by pattern, so once your app’s address is opened, it can turn up in that search.
Who This Affects
Claroc identified 24 open apps built by SpaceXSI and X staff, including a confidential onboarding plan, a sales territory map of 594 accounts, and advertising proposals. SpaceXSI took those 24 apps down after Claroc’s report and press questions, but Claroc says the apps of other Grok users and organizations were left open.
The apps run in a web browser rather than as native software, so the exposure isn’t tied to one specific device or operating system. If an app is published without a sign-in requirement, anyone who finds the link can open it, regardless of what device they’re using to do so.
How Grok Build’s Sharing Compares
Plenty of tools offer a “secret link” share option, and that’s the right mental model here. A secret link works like hiding your house key under the doormat. It feels private until someone knows where to look. Claroc found that when it published a Grok Build app, the access setting already proposed was “Anyone with the link.” By comparison, ChatGPT’s app sharing started at “Only me” in Claroc’s test.
| What users likely assumed | What the researcher found | Source |
|---|---|---|
| A random address keeps an app private | Passive DNS services logged the addresses, making them searchable | Claroc |
| Only a few apps were affected | 35,578 of 37,571 live apps (94.7%) opened without sign-in | Claroc |
| Internal tools held harmless data | Sales plans, patient lab results, and one timesheet app’s plain-text passwords were found | Claroc |
The Reaction
Claroc says it reported the issue to SpaceXSI on November 8. Ars Technica sent its questions on November 10, and SpaceXSI then took down the 24 staff apps. Claroc recommends serving shared apps on a hard-to-guess path rather than a separate hostname, so the link never becomes a DNS name.
In its answer to the press, quoted by Claroc, SpaceXSI said Grok apps are private until their creator chooses to share one. It said publishing takes several steps, including choosing between “Only you” and “Anyone with the link,” and that employee accounts default to “Only you.” Claroc’s reply is that ordinary users saw “Anyone with the link” already selected.
Our Take
Anyone who used Grok Build for work data should care right now. The fix on your end is cheap. The real damage comes from whatever was inside an open app, such as passwords or personal records, because a visitor may already have copied it.
The bigger lesson applies to every AI app builder. “Built in 30 seconds” is a great pitch for a tip calculator. It’s a bad fit for payroll or medical records unless the tool clearly requires a sign-in to view the app. Grok Build is still in beta, and beta software is a risky place to park confidential data.
What to Do Next: Check Your Grok Build Apps
The single most useful move is to review everything you’ve published. Take down any app with sensitive data. Check the script files each app loads for names, emails, and passwords, and change any password that appeared there. A password manager like Bitwarden or 1Password makes it much less painful to create new, unique passwords. Add a hardware security key such as a YubiKey to your important accounts if you want an extra lock on the door.
On Windows
Sign in to Grok Build in your browser and go through your published apps one by one. Take down anything holding customer, employee, or login data.
On Android
Use your phone’s browser to do the same review if you’re away from your desk. A quick removal now beats waiting until you’re back at your PC.
On the Web
Open one of your app links in a private or incognito window, where you aren’t signed in. If the app loads, so can anyone else’s browser. A failed load is not full proof, though, so also open the app’s access setting in Grok Build. For anything internal, Claroc says it should read “Invited users” or “Only you,” not “Anyone with the link.” Keep the Grok Build docs handy for xAI’s current guidance.
Wrapping Up
A random link felt private, and for more than 35,000 Grok Build apps, it wasn’t. Spend ten minutes reviewing what you’ve published, tightening access settings, and rotating any password that appeared in an app. Use Grok Build if you’re making throwaway tools with nothing sensitive inside. Stick with a sign-in-protected tool your company already approves if the app touches real customer, employee, or login data.