OpenMetadata accepts a caller-supplied post-authentication redirect target and appends the issued token to it. SamlLoginServlet reads the callback request parameter and stores it in the HTTP session without comparing it against any configured or registered destination, and the assertion consumer servlet later formats that stored value into a URL carrying the freshly issued JWT together with the account's email and name before sending the redirect. The OIDC and OAuth2 handler follows the same pattern with its own redirect parameter and the issued identity token. A request naming a destination the attacker controls therefore causes the server to deliver a valid token for whoever completes the login to that destination. Because the token authenticates API calls as that account, a user who follows such a link and authenticates hands over control of their account. Version 2.0.0 removes the caller-supplied callback parameter; no 1.x release validates it.

CVE-2026-81029 describes an open redirect vulnerability in OpenMetadata where the application accepts a caller-supplied post-authentication redirect target without validation. The SamlLoginServlet stores the callback parameter in the HTTP session without verifying it against any registered destination, and later appends the freshly issued JWT token along with the user's email and name to that URL before redirecting. The OIDC and OAuth2 handlers follow the same flawed pattern. An attacker can craft a malicious link pointing to an attacker-controlled destination, causing the server to deliver a valid authentication token to that destination when a victim completes login. This effectively results in full account takeover since the token authenticates API calls as the victim's account. Version 2.0.0 of OpenMetadata resolves the issue by removing the caller-supplied callback parameter entirely, while no 1.x release includes any validation of this parameter.