Report suspected vulnerabilities privately. Do not open a public issue for an unpatched vulnerability.

• GitHub: this repository's Security tab -> Report a vulnerability opens a private advisory visible only to you and the maintainers.
• Email: security@openagent.id.

We aim to acknowledge reports within 3 business days and to provide a remediation plan or a reasoned rejection within 14.

Security fixes ship in the latest release of agent-capability-token and on main. Upgrade to the latest release to receive them.

This repository defines and implements the ACT capability-token wire format. The following are always in scope and treated as high severity:

• Forgery or bypass of token signatures or verification steps
• Errors that let a verifier accept a malformed, expired, wrong-issuer, wrong-audience, or insufficiently scoped token
• Disclosure of private key material, seeds, or credentials
• Vulnerabilities in dependencies with a reachable exploit path

ACT envelopes use Ed25519 signatures over the exact CBOR-encoded claim bytes. If you believe you have found a weakness in that composition, please include a proof-of-concept against the conformance suite where possible - it shortens triage considerably.