Permissive Cross-domain Policy with Untrusted Domains Affecting flowise package, versions <3.1.2

flowise is a Flowiseai Server

Affected versions of this package are vulnerable to Permissive Cross-domain Policy with Untrusted Domains through the generateTextToSpeech handler in the text-to-speech endpoint. An attacker can make a victim’s browser send authenticated requests from any webpage by calling the TTS generate API, causing the browser to accept the response under a wildcard CORS policy. This lets an untrusted site invoke the text-to-speech endpoint using the user’s credentials and read the resulting stream, exposing the generated audio and any data returned by the request to the attacker.

Notes

• The bypass is specific to the TTS generate route because it carries chatflowId in the request body rather than the URL path, so origin checks that only inspect path-based chatflow routes do not cover this endpoint.
• The hardcoded wildcard applies even when the server’s configured CORS allowlist is restrictive, so deployments relying on getCorsOptions() for origin control are still exposed on this route.

• GitHub Commit
• Maintainer's Advisory