Medium · published October 19, 2026
Cross-Site Request Forgery (CSRF) vulnerability in Apache Camel OAuth component.
This issue affects Apache Camel: from 4.11.0 before 4.18.5, from 4.19.0 before 4.22.1.
The authorization code callback did not carry a state parameter binding it to the authorization request that started the flow, and the callback did not verify one. An authorization code obtained in any browser could therefore be redeemed at the callback and associated with whichever session presented it, which is login cross-site request forgery: a victim can be silently signed in as an identity the attacker controls, so that actions the victim then performs, and data they then submit, land in the attacker's account. The same unvalidated callback handling also allowed the post-authentication redirect target to be influenced, giving an open redirect from a trusted origin. The state check runs before the authorization code is redeemed, so these paths are reachable without any interaction with the identity provider.
Upgrade to Apache Camel 4.23.0, which fixes the issue. Users on the 4.18.x LTS releases stream should upgrade to 4.18.5. Users on the 4.22.x LTS releases stream should upgrade to 4.22.1. The authorization request now issues a state value bound to the session, and the callback rejects a request whose state is absent or does not match, stopping the route with a 400 response. For deployments that cannot upgrade immediately, terminate the authorization code flow in a component that performs its own state binding rather than relying on the Camel callback. Note that after upgrading, a deployment behind a proxy that drops or rewrites the callback query string will begin to see 400 responses, because the state parameter must survive the round trip.