security: move OG image execution behind flag

[peter-gy]

Makes the OG image generator function's automatic execution opt-in through --execute-opengraph-generators flag to reduce risk of Remote Code Execution vulnerability.

[vercel]

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Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Jul 14, 2026 10:17am

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[cubic-dev-ai]

All reported issues were addressed across 11 files

Architecture diagram

sequenceDiagram
    participant User as Client Browser
    participant CLI as CLI (marimo run)
    participant Server as Starlette Server
    participant SM as SessionManager
    participant AssetEP as Assets Endpoint (og_thumbnail)
    participant HomeEP as Home Endpoint
    participant IndexEP as Index Endpoint
    participant OGMod as resolve_opengraph_metadata
    participant FS as File System
    participant NB as Notebook App (generator fn)

    Note over User,NB: NEW: OpenGraph generator execution gated by flag

    User->>Server: GET / (index) or /api/home/files or /api/og-thumbnail

    alt Index page request
        Server->>IndexEP: handle index request
        IndexEP->>SM: get execute_opengraph_generators
        SM-->>IndexEP: flag (bool)
        IndexEP->>OGMod: resolve_opengraph_metadata(execute_generator=flag)
        OGMod->>FS: read notebook file for og config
        FS-->>OGMod: config (maybe with generator name)
        alt generator declared AND execute_generator == True
            OGMod->>NB: execute _run_opengraph_generator()
            NB->>NB: run notebook-defined code
            NB-->>OGMod: dynamic metadata (e.g., title, image)
        else generator absent OR execute_generator == False
            Note over OGMod: skip generator execution (safe default)
        end
        OGMod-->>IndexEP: resolved OpenGraphMetadata
        IndexEP-->>User: HTML with og tags
    else Home endpoint (file listing) request
        Server->>HomeEP: get_files_with_metadata()
        HomeEP->>SM: get execute_opengraph_generators
        SM-->>HomeEP: flag
        HomeEP->>OGMod: resolve_opengraph_metadata(execute_generator=flag) per file
        OGMod->>FS: read file
        OGMod-->>HomeEP: metadata
        HomeEP-->>User: FileInfo with og title (static only if flag false)
    else OG thumbnail request
        User->>Server: GET /api/og-thumbnail?file=...
        Server->>AssetEP: og_thumbnail()
        AssetEP->>SM: get execute_opengraph_generators
        SM-->>AssetEP: flag
        AssetEP->>OGMod: resolve_opengraph_metadata(execute_generator=flag)
        OGMod->>FS: read file config
        OGMod-->>AssetEP: metadata
        AssetEP-->>User: image redirect or static OG image
    end

    Note over CLI,SM: Flag originates from CLI or ASGI builder
    CLI->>Server: start(execute_opengraph_generators=True/False)
    Server->>SM: SessionManager(execute_opengraph_generators=flag)

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Re-trigger cubic</sub>

[dmadisetti]

Thanks! I think this is a great compromise

[github-actions]

🚀 Development release published. You may be able to view the changes at https://marimo.app?v=0.23.15-dev16