CVE-2026-120233 Details

A vulnerability allowing information disclosure has been identified in the AG-UI Protocol, specifically in versions of the AG-UI package through 0.0.58. The issue resides in the HttpAgent component, within the file sdks/typescript/packages/client/src/agent/http.ts. The vulnerability arises because HttpAgent follows redirects by default, forwarding credentials and the run request to a server-chosen origin. This behavior can be exploited by a malicious or compromised agent endpoint to exfiltrate sensitive information, such as tenant credentials and the full run body, to an arbitrary origin. The vulnerability can be exploited remotely, and the published pull request to address this issue is currently awaiting acceptance.

The suggested remediation is to modify the HttpAgent's request initialization to include a redirect option that prevents automatic following of redirects. Instead, redirects should be handled as errors. Additionally, it's important to ensure that the run request body and authorization headers are not forwarded across origin changes.