CVE-2026-48520: Langflow: Unauthenticated Shareable Playground arbitrary local or S3 file read

The “Shareable Playground” (or “Public Flows” in code) contains a potential arbitrary file-read vulnerability, depending on the exact flow configuration used.

By making a flow public, public execution of the flow is allowed. The execution request can contain a list of files that gets read by Langflow and fed into the LLM. The files path can be any path supported by the storage - it can be either a local file or S3 path if supported by the local configuration