Valtimo is an open source business process and case management platform. When opening a form in Valtimo, the access token (JWT) of the user is exposed to "api.form.io" via the the "x-jwt-token" header. An attacker can retrieve personal information from this token, or use it to execute requests to the Valtimo REST API on behalf of the logged-in user. This issue is caused by a misconfiguration of the Form.io component. The following conditions have to be met in order to perform this attack: An attacker needs to have access to the network traffic on the "api.form.io" domain; the content of the "x-jwt-token" header is logged or otherwise available to the attacker; an attacker needs to have network access to the Valtimo API; and an attacker needs to act within the time-to-live of the access token. The default TTL in Keycloak is 5 minutes. Versions 10.8.4, 11.1.6 and 11.2.2 have been patched.