Security fixes target the latest published marimo-export release and the main branch. The project will publish a broader support policy when it maintains more than one release line.

Do not open a public issue with vulnerability details.

Use GitHub private vulnerability reporting for this repository when it is available. Otherwise, open a minimal public issue asking the maintainers for a private reporting path. Do not include technical details, reproduction steps, credentials, hostnames, logs, screenshots, notebook source, or exported data in that issue.

Include these details in the private report:

• Affected version or commit.
• The affected boundary, such as notebook or exporter execution, live transport and authentication, repository storage, directory replacement, export integrity, browser loading, interactive mounting, or package distribution.
• Impact and minimal reproduction steps.
• Any known mitigation.

Never include real secrets. Identify the credential type and location when a committed or logged credential is involved, then rotate it before sharing more evidence.

Preparing or capturing an export executes notebook and exporter code with the producer process's filesystem, credential, package, and network access. Managed process ownership supplies startup, timeout, cancellation, and cleanup. It is not an operating-system security sandbox.

The exporter, the Python reader, and marimo-export verify compare asset bytes with the SHA-256 digests in index.json. The browser reader validates the canonical index, each asset's size, and native framing, so a same-sized change made in transit, in storage, or in a CDN or HTTP cache reaches its loaders. Serve exports over HTTPS from a host trusted as much as the application page. The application authenticates the publisher and delivery origin. Mounting an AnyWidget, Vega-Lite chart, or custom interactive representation grants that code the browser page's authority. Exported HTML remains untrusted markup until the application applies its rendering and sanitization policy.

Read Integrity and trust for the public model and Architecture for internal ownership.