Definition
Plain language
A standard way for one app to grant another app access to your account without sharing the password.
As stated in the literature
An open authorization protocol that delegates resource access via tokens, widely used by cloud and SaaS APIs and a frequent target for credential-exfiltration concerns in AI agents.
Why it matters: Token-based delegation is how modern apps integrate safely, but it also makes leaked tokens a tempting target for compromised AI agents.
For example, when you click 'Sign in with Google' to use a new app, OAuth grants the app a token without ever giving it your Google password.
Heard on the show
“… been able to escalate to root, it would almost certainly have installed cloud SDKs and configured OAuth credentials, which would have given it programmatic access to email, calendar, cloud services. …”Episode 049 — An AI Agent Reached for Root in Twelve Minutes, Without Being Attacked