+ "details": "### Summary\n\nSeveral NiceGUI APIs that execute methods on client-side elements (`Element.run_method()`, `AgGrid.run_grid_method()`, `EChart.run_chart_method()`, and others) use an `eval()` fallback in the JavaScript-side `runMethod()` function. When user-controlled input is passed as the method name, an attacker can inject arbitrary JavaScript that executes in the victim's browser.\n\nAdditionally, `Element.run_method()` and `Element.get_computed_prop()` used string interpolation instead of `json.dumps()` for the method/property name, allowing quote injection to break out of the intended string context.\n\n### Attack Vector\n\nAn attacker crafts a malicious URL with a payload as a query parameter. If the application passes this parameter as a method name to any of the affected APIs, the payload is sent to the client via WebSocket and executed via `eval()`.\n\n**Example:** `/?method=alert(document.cookie)` combined with application code like:\n```python\nelement.run_method(user_provided_method_name)\n```\n\n### Impact\n\n- Cookie/token theft\n- DOM manipulation (phishing, fake login forms)\n- Actions performed as the victim user\n\n### Affected Methods\n\n1. `Element.run_method()`\n2. `Element.get_computed_prop()`\n3. `AgGrid.run_grid_method()`\n4. `AgGrid.run_row_method()`\n5. `EChart.run_chart_method()`\n6. `JsonEditor.run_editor_method()`\n7. `Xterm.run_terminal_method()`\n8. `Leaflet.run_map_method()`\n9. `Leaflet.run_layer_method()`\n10. `LeafletLayer.run_method()`\n\n### Fix\n\n1. Use `json.dumps()` for proper escaping of method/property names in `run_method()` and `get_computed_prop()`\n2. Remove the `eval()` fallback from `runMethod()` in `nicegui.js` — method names that are not found on the element now raise an error instead of being evaluated as arbitrary JavaScript\n\n### Migration\n\nCode that previously passed JavaScript functions as method names needs to use `ui.run_javascript()` instead:\n\n```python\n# Before:\nrow = await grid.run_grid_method('g => g.getDisplayedRowAtIndex(0).data')\n\n# After:\nrow = await ui.run_javascript(f'return getElement({grid.id}).api.getDisplayedRowAtIndex(0).data')\n```",
![advisory-database[bot]](https://avatars.githubusercontent.com/in/21409?v=4&size=40){kind=avatar}
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