A single prompt was enough to hijack every AI agent in an AWS account, Zenity researchers found

Zenity Labs researchers revealed that a single publicly accessible AI agent on Amazon's Bedrock AgentCore was sufficient to take control of all AgentCore agents within the same AWS account and region. The attack exploited an internal AWS interface for temporary cloud credentials, allowing agents to access it without restrictions. AWS has since patched the vulnerability and significantly tightened the default permissions for agents.