v0.15 is out: rules that were silently dropped on the shipped engine now run, and scans skip your test and mock files by default. Read more →
MEDIUM AI PREVALENCE: MEDIUM auth.jwt.jose-no-audience

A JWT is verified with jose jwtVerify(...) but no audience option is passed, so the aud claim is never checked.

Why AI tools produce this: AI coding tools produce this regularly, typically when prompted for a shortcut or a quick fix.

Why this matters

A token minted for another service that trusts the same issuer or signing key can then be replayed here: a confused deputy (CWE-345). For an MCP or OAuth 2.1 resource server this is exactly the RFC 9068 / RFC 8707 audience binding the spec requires.

Pass the audience you expect (your resource identifier): await jwtVerify(token, JWKS, { audience: 'https://mcp.example.com/mcp' });

VULNERABLE
vulnerable.ts
import { createRemoteJWKSet, jwtVerify } from 'jose';

const JWKS = createRemoteJWKSet(new URL('https://auth.example.com/.well-known/jwks.json'));

export async function verify(token: string) {
  // ruleid: auth.jwt.jose-no-audience
  const { payload } = await jwtVerify(token, JWKS, { issuer: 'https://auth.example.com' });
  return payload;
}
SAFE
safe.ts
import { createRemoteJWKSet, jwtVerify } from 'jose';

const JWKS = createRemoteJWKSet(new URL('https://auth.example.com/.well-known/jwks.json'));

export async function verify(token: string) {
  // ok: auth.jwt.jose-no-audience
  const { payload } = await jwtVerify(token, JWKS, {
    issuer: 'https://auth.example.com',
    audience: 'https://mcp.example.com/mcp',
  });
  return payload;
}

Suppressing this rule

If a finding is a genuine false positive, scope the suppression to the exact line and leave a reason, never disable the rule project-wide. Disable directives are line-scoped by design.

// oauthlint-disable-next-line auth.jwt.jose-no-audience -- <reason>

References

https://datatracker.ietf.org/doc/html/rfc9068 ↗https://datatracker.ietf.org/doc/html/rfc8707 ↗https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.3 ↗