Key facts
- Claroc's Asaf Aprozper said more than 35,000 of 43,601 grok.me links opened the app and its stored data.
- Claroc found 24 SpaceXSI-built apps exposing internal material, including a sales territory map of 594 accounts.
- Exposed data included a Tesla service-center scorecard naming 22 technicians and a healthcare roster of about 3,565 employees.
- A Cursor representative said Grok Build apps are private by default; Aprozper said his tests contradict that.
- SpaceXSI removed the 24 exposed links within hours of Ars Technica's questions, and all returned an app not found error.
Grok Build, the coding agent from SpaceXSI, exposed confidential information from thousands of users through the links that let people share the apps they build, according to research by security firm Claroc reported by Ars Technica on November 10, 2026.
Grok Build randomizes share URLs so only people with the exact address can open an app. Claroc found the random words sit to the left of the grok.me domain, which lets passive DNS services, which log lookups of previously unseen addresses, capture the links. Asaf Aprozper, Claroc's co-founder and CTO, said a passive DNS search returned 43,601 links ending in grok.me, and more than 35,000 of them, nearly 95 percent, opened the app and all data it stored.
The exposed material included internal business plans, ad proposals, medical exam results, a cruise line galley checklist and employee names and ID numbers. Claroc found 24 apps built by SpaceXSI itself, including a confidential onboarding plan for an enterprise sales hire, a sales territory map of 594 accounts and advertising proposals.
Other affected organizations listed by Claroc include Tesla, whose service-center scorecard named 22 technicians with productivity and bonus status, a US Navy ship engineering contractor with a roster of 108 people, a healthcare company with about 3,565 employees listed by name and ID, and a Peruvian construction company with a dashboard of 3,784 worker medical exams.
Aprozper said he is notifying the companies. After speaking with the luxury cruise company's CISO, he said it pulled in its whole security team and was working to contain the exposure. A Cursor representative said Grok Build apps are private by default and nothing goes public unless the creator chooses to share it; Aprozper's tests, which he said showed links default to anyone with the link, contradict that. SpaceXSI began removing the 24 links within hours of Ars Technica's questions, and all returned an app not found error.