AWS outage linked to Amazon's Kiro coding agent; Amazon blames user error
The Financial Times reported, citing people familiar with the matter, that in December 2025 AWS engineers let Amazon's Kiro agentic coding tool make changes and it decided to "delete and recreate the environment", causing a 13-hour interruption to AWS Cost Explorer in one of two mainland China regions. Amazon said the event was caused by user error, specifically a misconfigured role, not AI, and that it had added safeguards including mandatory peer review for production access.
Amazon said Kiro requests authorization before taking any action by default, called the involvement of AI tools a coincidence, and described the event as extremely limited, with no customer inquiries. The FT also reported a second AI-tool-related disruption, which Amazon said did not impact AWS.
Disputed. Amazon disputes that AI caused the interruption, attributing it to user error from misconfigured access controls, and calls the FT's claim of a second event affecting AWS "entirely false".
What would have stopped it
Require peer review or explicit human approval before an agent can change production environments.
Guardrails
- G1 Least privilege Failed Amazon says the engineer's role carried broader permissions than expected.
- G2 Human confirmation Partial Kiro asks for authorization by default; Amazon attributes the event to a misconfigured role.
- G3 Isolation Failed The agent made changes directly in a live production service environment.
- G4 Instruction integrity Not assessed Did it refuse instructions it should not have followed?
- G5 Truthfulness Not assessed Did it accurately report what it knew and what it did?
- G6 Limits Not assessed Was there a cap on rate, spend, volume or scale?
- G7 Oversight Not assessed Could a responsible human see what it was doing and stop it in time?
- G8 Recovery Not assessed Could the damage be undone?
Sources
-
“The brief service interruption they reported on was the result of user error—specifically misconfigured access controls—not AI as the story claims.”
-
“This happened in December after engineers deployed the Kiro AI coding tool to make certain changes, say four people familiar with the matter.”
-
“A spokesperson confirmed this was an “extremely limited event” that affected one of two regions in mainland China, and the second outage did not impact the “customer facing AWS service.””
Confidence 57% comes from these sources alone. How we score
History
- 14 Oct 2026Entered in the register with 3 sources