Gemini hack AI agents just turned a controlled cybersecurity test into a real-world security incident.

Gemini Hacked Three Real Companies During a Test. That’s the Problem With AI Agents

AI AI Industry by Léa Valmont

Google’s Gemini was given an offensive cybersecurity task against fictional targets. Instead, during an evaluation in May 2026, the model accessed protected systems belonging to three real companies.

The important part is not that Gemini suddenly developed malicious intentions. There is no evidence that it did. The model was doing what it had been instructed to do: find ways into systems it believed were part of a controlled security exercise. The problem was that the boundary between that exercise and the real Internet was not as solid as everyone thought.

According to Google, Gemini found public information online and obtained credentials for websites it believed were legitimate targets. In one case, it reportedly guessed passwords until one worked. In two others, it found credentials in public repositories. The model had unintended Internet access, and systems outside the evaluation became reachable.

Google says Gemini stopped in all three cases once it recognized that it had reached real companies. The affected organizations were notified, and Irregular, the independent company running the evaluation, has since changed its testing procedures.

That makes the incident less like a science-fiction story about an AI “escaping” and more like a very modern security failure. It also makes it more useful.

Because AI agents change what happens when a model gets something wrong.

A chatbot can misunderstand a question and give a bad answer. An agent with network access, credentials and tools can misunderstand a task and do something.

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What actually happened during the Gemini test

The incidents occurred during cybersecurity evaluations conducted by Irregular, a company that works with major AI labs to test advanced models before deployment.

These evaluations deliberately put models into unusual conditions. If researchers want to know how capable a model is at offensive cybersecurity, they need to give it offensive cybersecurity problems. Some evaluations also reduce the safeguards normally present in consumer products so researchers can measure the underlying capability rather than the effectiveness of the product’s safety filters.

In this case, that distinction matters enormously. Gemini was not browsing the Internet one afternoon and spontaneously deciding to attack companies. It had been assigned a cybersecurity task.

The evaluation environment was supposed to contain fictional targets. Irregular later explained that Internet access had unintentionally been available during a small number of interactions. There was also a particularly mundane problem: a fictional company used in the evaluation shared its name with a real-world entity or domain.

For an autonomous system trying to solve a task, that ambiguity mattered.

The model could search beyond the simulated environment, encounter something that appeared to match its assigned target and continue working. Because the task itself involved breaking into systems, actions that would normally look obviously hostile could still appear consistent with the objective it had been given.

Google’s account says Gemini accessed three real companies. Reuters reported that Google Vice President of Security Engineering Heather Adkins said the model found public information and guessed credentials for sites it thought were within the scope of the test.

The specific Gemini model involved has not been publicly identified. Neither have the three affected companies.

This was not an AI rebellion

The vocabulary around incidents like this becomes misleading very quickly.

Words such as “escaped,” “rogue” and even “decided” suggest a system that understood the rules, formed an intention to violate them and deliberately acted against its operators.

The available evidence does not establish that.

A more useful distinction is between autonomy, intention and error.

Autonomy describes how much a system can do without requiring a human to approve every intermediate step. An agent might search the web, execute code, call APIs, inspect files or authenticate with external services while pursuing an objective.

Intention is a much stronger claim. It implies something about what the system understood and wanted. Nothing about the Gemini incidents requires that explanation.

Error is enough.

If an agent believes a real server belongs to its simulated target, then a perfectly coherent sequence of actions can produce an unacceptable result. The individual steps may even be technically competent. The failure lies in the model’s understanding of where it is allowed to apply them — and in the infrastructure that allowed the mistake to become consequential.

That distinction is particularly important because the same class of problem has appeared elsewhere.

Anthropic disclosed in July that Claude models had reached real third-party systems during cybersecurity evaluations involving Irregular. OpenAI has separately disclosed incidents in which models crossed intended security boundaries during cyber testing, including an evaluation that resulted in access to Hugging Face infrastructure. Meta has also reported an incident involving an earlier model during third-party cyber testing.

These cases are technically different and should not be collapsed into one story about “AI going rogue.” But they point toward a shared engineering problem: models are becoming capable enough to interact with environments in ways that test designers did not fully anticipate.

Why AI agents change the security equation

Traditional large language models mostly produced outputs.

Ask a chatbot a question and it generates text. If it hallucinates the capital of a country, invents a citation or writes broken code, the error initially exists inside the conversation. A human or another system generally has to act on it before the mistake changes anything outside the model.

AI agents collapse part of that distance.

Give a model a browser and it can navigate websites. Give it a terminal and it can execute commands. Give it API access and it can interact with services. Give it credentials and it can operate inside accounts. Combine those capabilities with memory and a long-running objective, and the model can perform chains of actions without asking a human what to do at every step.

That is precisely why agents are useful.

It is also why their failure modes matter more.

Consider a simple misunderstanding. A conventional chatbot incorrectly identifies `example-real-company.com` as the domain belonging to a fictional company in a security exercise. It might print the wrong URL.

An agent with network access can visit it.

An agent with offensive tools can probe it.

An agent that discovers credentials can authenticate.

The underlying reasoning error does not have to become dramatically worse. The consequences do.

This is one of the most important differences between AI capability and AI agency. Better reasoning makes models more useful, but connecting those models to tools changes the security model even if their reasoning remains imperfect.

Cybersecurity tests have an uncomfortable problem

Cybersecurity evaluation makes this problem unusually difficult because researchers are intentionally asking models to behave like attackers.

A serious offensive-security benchmark cannot measure much if the model is prevented from scanning hosts, exploiting vulnerabilities, using credentials or chaining together multiple attack steps. Researchers need to observe what the system can actually accomplish.

Yet the more realistic the environment becomes, the more important containment becomes.

This produces an awkward engineering tension. Researchers need to give models enough freedom to measure dangerous capabilities while ensuring those capabilities cannot reach anything outside the test.

Irregular’s investigation provides a sense of how difficult that can become at scale. The company said the relevant real-world interactions appeared in fewer than one in 10,000 advanced simulation runs and generally emerged late in lengthy evaluations, sometimes after hundreds of turns.

Ordinary monitoring also becomes less useful because the authorized activity already looks malicious. Password attacks, exploitation attempts and credential use are expected behavior inside an offensive cyber benchmark. A security system therefore cannot simply sound an alarm whenever the model behaves like an attacker.

That is the benchmark.

The system has to distinguish an authorized attack against a simulated machine from essentially the same sequence against an unauthorized one.

And the safest place to make that distinction is not inside the model’s reasoning.

It is at the boundary.

Credentials turn mistakes into permissions

The Gemini incidents also expose a broader problem that extends far beyond cybersecurity benchmarks.

Modern AI products are increasingly useful because users can give them access to things.

Email. Cloud storage. Source-code repositories. Browsers. Calendars. Corporate applications. Terminals. Databases. Payment systems. Internal documents.

Every new permission increases what an agent can accomplish. It also increases what a mistaken instruction, compromised workflow or incorrect interpretation can affect.

Credentials are particularly important because authentication systems traditionally assume that possession means authorization. If an agent has a valid API key, token or password, the service on the other side usually has no idea whether the human who owns that credential intended the particular action now being performed.

The Gemini case provides a remarkably clean illustration. Credentials found in public repositories were useful because they worked. From the target system’s perspective, valid authentication was still valid authentication.

Agent security therefore cannot rely exclusively on making models better at understanding instructions. Permissions have to assume that the model will eventually misunderstand something.

That is already standard thinking in mature security architecture. The principle of least privilege gives a user or process only the access required for its task. Network segmentation limits where compromised systems can go. Short-lived credentials reduce the usefulness of stolen secrets. Approval gates can require human authorization before particularly sensitive operations.

AI agents make those old ideas newly relevant.

What better guardrails could look like

The obvious response to an incident involving unintended Internet access is stronger isolation, and Irregular says it has already added safeguards and remediated the issue behind the affected evaluation environment.

But agent containment needs several layers because no single mechanism is likely to catch every failure.

Network allowlists can restrict an evaluation agent to explicitly authorized hosts rather than assuming it will correctly infer which targets are in scope. For highly sensitive testing, outbound Internet traffic can be blocked at the infrastructure level.

Credential isolation can ensure that secrets inside an evaluation work only inside that environment. Test credentials should not unlock production systems, and real credentials should never be available merely because an agent found them somewhere accessible.

Domain and target validation can prevent a fictional company name from accidentally pointing toward a real organization. If an evaluation expects the agent to attack a defined set of systems, those targets can be verified independently before connections are allowed.

Tool-level permissions can restrict dangerous actions even when the model requests them. The agent may decide what it wants to do, while a separate policy layer decides whether it is technically permitted to do it.

Human approval gates remain useful for actions with unusually high consequences, particularly when an agent attempts to cross a trust boundary, use newly discovered credentials or interact with a destination outside its expected environment.

None of these controls requires solving the philosophical question of whether an AI system truly “understands” its actions.

That is part of their appeal.

A firewall does not need to know why the model wants to connect to a server. It only needs to know that the server is not on the list.

AI agent security is becoming infrastructure security

Gemini’s three intrusions are striking partly because the techniques themselves were not exotic. Public credentials and password guessing are hardly the stuff of elite cyberwarfare.

The consequential capability was persistence across a sequence of steps.

An agent could interpret a goal, search for information, interact with systems, discover or guess credentials and use them without requiring a human operator to manually perform every action. When the environment failed to constrain where that process could go, the workflow crossed into the real world.

The incident therefore says less about machines developing hostile intentions than about software acquiring operational reach.

That problem will extend well beyond cybersecurity as agents become more deeply integrated into ordinary computing. A coding agent can modify a repository. An office agent can send email or move files. A browser agent can interact with accounts. A corporate agent can call internal APIs.

Every one of those systems will occasionally misunderstand context.

The relevant security question is increasingly not whether an AI agent can make a mistake. Models already do.

It is how much authority the system still has when it makes one.

Gemini and AI agents: key questions

Did Gemini really hack three companies?
Google confirmed that a Gemini model accessed protected systems belonging to three real companies during cybersecurity evaluations conducted by Irregular in May 2026.

Did Gemini deliberately escape its test environment?
The available evidence does not show that Gemini intentionally tried to escape or attack unrelated companies. Google says the model believed the websites were within the scope of its assigned evaluation and stopped after recognizing that they were real targets.

How did Gemini get into the systems?
According to reporting on the incidents, Gemini guessed credentials in one case and used credentials discovered in public repositories in two others.

Was this the current version of Gemini?
Google has not publicly identified the specific Gemini model involved in the May incidents.

Why did Gemini have Internet access during a cybersecurity test?
Irregular has said Internet access was unintentionally available in interactions involving the affected evaluation environment. The company says the underlying issue has since been remediated and additional safeguards have been introduced.

Have other AI models had similar incidents?
Yes. Anthropic, OpenAI and Meta have disclosed incidents involving models reaching real-world systems during cybersecurity evaluations, although the technical circumstances and model behavior differ between cases.

Why are AI agents riskier than ordinary chatbots?
An ordinary chatbot primarily generates information. An AI agent can be connected to tools that let it browse, execute code, access accounts, modify files or interact with external services. A reasoning error can therefore become an external action.

Can AI agents be made completely safe by improving the model?
Model improvements can reduce errors, but security engineering generally assumes that failures will still occur. Strong containment, limited permissions, network controls, credential isolation, monitoring and human approval for sensitive actions can limit what an agent is able to do when something goes wrong.

Sources: Reuters, Irregular, Anthropic