https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-03T15:49:06.453135+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/cve-2026-39987 CVE-2026-39987 — marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass 2026-10-03T15:49:06.454764+00:00

Affected: marimo-team marimo

marimo is a reactive Python notebook. Prior to 0.23.0, Marimo has a Pre-Auth RCE vulnerability. The terminal WebSocket endpoint /terminal/ws lacks authentication validation, allowing an unauthenticated attacker to obtain a full PTY shell and execute arbitrary system commands. Unlike other WebSocket endpoints (e.g., /ws) that correctly call validate_auth() for authentication, the /terminal/ws endpoint only checks the running mode and platform support before accepting connections, completely skipping authentication verification. This vulnerability is fixed in 0.23.0.

 https://cve.radiocsirt.org/vuln/ghsa-2679-6mx9-h9xc GHSA-2679-6mx9-h9xc — Marimo: Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass 2026-10-03T15:49:06.454816+00:00

Affected: PyPI: marimo

## Summary

Marimo (19.6k stars) has a Pre-Auth RCE vulnerability. The terminal WebSocket endpoint `/terminal/ws` lacks authentication validation, allowing an unauthenticated attacker to obtain a full PTY shell and execute arbitrary system commands.

Unlike other WebSocket endpoints (e.g., `/ws`) that correctly call `validate_auth()` for authentication, the `/terminal/ws` endpoint only checks the running mode and platform support before accepting connections, completely skipping authentication verification.

## Affected Versions

Marimo <= 0.20.4

## Vulnerability Details

### Root Cause: Terminal WebSocket Missing Authentication

`marimo/_server/api/endpoints/terminal.py` lines 340-356:

```python @router.websocket("/ws") async def websocket_endpoint(websocket: WebSocket) -> None: app_state = AppState(websocket) if app_state.mode != SessionMode.EDIT: await websocket.close(...) return if not supports_terminal(): await websocket.close(...) return # No authentication check! await websocket.accept() # Accepts connection directly # ... child_pid, fd = pty.fork() # Creates PTY shell ```

Compare with the correctly implemented `/ws` endpoint (`ws_endpoint.py` lines 67-82):

```python @router.websocket("/ws") async def websocket_endpoint(websocket: WebSocket) -> None: app_state = AppState(websocket) validator = WebSocketConnectionValidator(websocket, app_state) if not await validator.validate_auth(): # Corr…