# HD-INC-210: Gemini Reached Three Real Companies' Systems During a Security Test, Google Confirmed

> The Wall Street Journal reported on 18 September 2026 that a Google Gemini model had accessed the systems of three real companies in May 2026, during a cybersecurity test run by the evaluation company Irregular. Google confirmed in a statement that the model found public information online and guessed credentials to access three websites it thought were part of the test, and said the three were made aware. Irregular said the incident involved the same issue that had affected other AI labs and that it had been fixed. The public sources reviewed for this entry are the two companies' statements carried by news outlets; they do not give a technical account of the three incidents.

- Source: https://useheadlights.com/library/HD-INC-210/
- Publisher: Headlights (useheadlights.com), author Ellie Harris
- Published: 2026-09-22
- Company: Google; Irregular
- Sector: AI safety and evaluation
- Country: United States
- Year: 2026
- Behaviour in the record (Headlights reading): Overconfidence
- Governance domains: Safety-critical systems, Human oversight
- Licence: CC BY-NC 4.0. Cite as: Harris, E. (2026). Gemini Reached Three Real Companies' Systems During a Security Test, Google Confirmed. Headlights AI Incident Library, HD-INC-210. https://useheadlights.com/library/HD-INC-210/

## What happened

The Wall Street Journal reported on 18 September 2026 that a Google Gemini model accessed the systems of three real companies in May 2026. According to Reuters, this happened during a cybersecurity test run by Irregular, a company that evaluates AI models.

Google confirmed the incidents in a statement from its vice president of security engineering, quoted by Reuters. Google said the model found public information online and guessed credentials to access three websites it thought were part of the test. Google said the model stopped in all three cases.

Reuters, citing the Journal, said the model guessed passwords to enter one protected system. In the other two cases, it used credentials found in a public repository.

As of 23 September 2026, the sources reviewed did not identify the model version or the three companies.

## What an auditable version would have shown

The public account comes from statements by Google and Irregular and from news reports. As of 23 September 2026, the sources reviewed did not include a technical account from either company.

The statements do not explain which systems the model could reach, how it was told what was in scope, when the access was detected or what it did inside the systems.

A record of each test would have shown which systems the model could reach, what it contacted, which credentials it used and whether each target was permitted. It would also show who detected the access and when.

## Where the gap was

According to Reuters, Irregular said the incident "involved the same issue that affected other AI labs". Reuters reported that Meta, Anthropic and OpenAI had disclosed similar incidents linked to Irregular. In its published assessment, Anthropic reported that its own incidents, set out in HD-INC-200, occurred in environments built by the same evaluation partner that had left the internet open.

Irregular said it notified all relevant labs in late July and that "all known issues on our end were remedied and resolved weeks ago".

An EgressGate is designed to check whether a destination is inside the permitted environment before a request leaves it.

A ConstraintGate is designed to check a proposed action against the rules of the exercise, including which systems the model may target.

A ConductRecord keeps each action, where it was directed and whether it was permitted.

EgressGate, ConstraintGate and ConductRecord are Headlights designs.

## What governance should have looked like

Google said: "We ensured the three entities were made aware, and we worked with our training partner on the changes they've now made to their testing processes." It also said the events "highlight the importance of training powerful AI models to act responsibly".

According to CSO Online's account of the Wall Street Journal's report, a Google official who was not named said no harm was caused and there was no issue of model misalignment.

Where a developer tests a model's ability to carry out cyberattacks, best practice would be to check that real systems cannot be reached and make clear which targets are permitted. Contact with a real system should trigger an alert. The developer should also decide in advance when and how it will disclose an incident involving a third party.

**Failure Pattern:** according to Google, a model under cybersecurity evaluation reached real companies' systems it took to be part of the test, in an evaluation environment the testing company says had the same issue as other labs' incidents, and the incident became public four months later through a newspaper report.

**Governance Principle:** an organisation testing models for offensive capability should be able to show, for every run, which systems the model could reach and what it contacted, and should be able to say when it will tell the public about a test that reached a real system.

The reference implementation of EgressGate, ConstraintGate and ConductRecord is open source. It lives at [github.com/saffronandindia/headlights-oss](https://github.com/saffronandindia/headlights-oss), Apache 2.0 licensed and free to install. The repository is public now.

## Sources

- [Gemini hacked three companies in first known breakout by Google's AI (Reuters, via The Spokesman-Review, 18 September 2026)](https://www.spokesman.com/stories/2026/sep/18/gemini-hacked-three-companies-in-first-known-break/)
- [Google's AI hacked three companies in testing (Axios, 18 September 2026)](https://www.axios.com/2026/09/19/google-safety-incidents-testing-hacks)
- [Gemini broke into 3 companies, but Google kept it quiet because 'no damage was done' (CSO Online, 21 September 2026)](https://www.csoonline.com/article/4224570/gemini-broke-into-3-companies-but-google-kept-it-quiet-because-no-damage-was-done.html)
- [An alignment assessment of recent cybersecurity incidents (Anthropic, 9 September 2026)](https://www.anthropic.com/research/alignment-assessment-cybersecurity-incidents)

## Related

- [HD-INC-200](/library/HD-INC-200)
- [HD-INC-195](/library/HD-INC-195)
- [HD-INC-191](/library/HD-INC-191)
