Activepieces is an open source AI workflow automation platform. Prior to 0.83.0, the /api/redirect OAuth callback endpoint embeds the user-supplied code query parameter directly into an inline script block without proper escaping. A crafted request to /api/redirect with a malicious code value can break out of the script context and execute arbitrary JavaScript in the Activepieces origin when a logged-in user opens it. An unauthenticated attacker can access the victim's session tokens or make authenticated API calls on the victim's behalf. This issue is fixed in version 0.83.0.