djust provides Phoenix LiveView-style reactive server-side rendering for Django with Rust-powered performance. Prior to version 1.0.7, the djust live transport resolves the LiveView to mount from a client-supplied dotted path by calling `__import__(module_path, ...)`. The module is imported — running its top-level code (import side effects) — before the framework checks that the resolved object is a `LiveView` subclass and before any per-view authentication. The `LIVEVIEW_ALLOWED_MODULES` allowlist that should contain this is fail-open (`if allowed_modules:` — skipped when the setting is unset, the framework default) and uses loose `startswith` matching. An unauthenticated WebSocket client (the WS handshake does not require auth; per-view auth runs only after import + instantiate) can therefore send a `mount` / `live_redirect_mount` / `url_change` frame (or an SSE mount) with `view = "<any.importable.module>.AnyName"` and cause the server to import — and execute the top-level code of — any importable Python module by name. Version 1.0.7 fixes the issue with a fail-closed resolution gate (`djust._view_resolution.is_view_import_allowed`): a client view path resolves only if (a) its module is already loaded (`sys.modules` — so resolving runs no new code; URL-routed views loaded by URLconf at startup keep working with zero config) or (b) it matches `LIVEVIEW_ALLOWED_MODULES` on a module-segment boundary (explicit opt-in for lazily-imported views). The gate runs before `__import_…

Affected: PyPI: djust

### Impact The djust live transport resolves the LiveView to mount from a **client-supplied dotted path** by calling `__import__(module_path, ...)`. The module is imported — running its **top-level code (import side effects)** — *before* the framework checks that the resolved object is a `LiveView` subclass and *before* any per-view authentication. The `LIVEVIEW_ALLOWED_MODULES` allowlist that should contain this is **fail-open** (`if allowed_modules:` — skipped when the setting is unset, the framework default) and uses loose `startswith` matching.

An **unauthenticated** WebSocket client (the WS handshake does not require auth; per-view auth runs only after import + instantiate) can therefore send a `mount` / `live_redirect_mount` / `url_change` frame (or an SSE mount) with `view = "<any.importable.module>.AnyName"` and cause the server to import — and execute the top-level code of — **any importable Python module by name**.

**Consequences:** server-side execution of arbitrary importable modules' import-time side effects by an unauthenticated client (effectively RCE-by-proxy on any host that has a side-effectful importable module), denial of service (import bombs / expensive dependency trees), and a module/class **enumeration oracle** via distinct error strings.

Reproduced end-to-end: an unauthenticated `WebsocketCommunicator` `mount` frame with the allowlist unset imported and executed a sentinel non-LiveView module before the "not a LiveView subclass" rejection.

### Af…

Affected: PyPI: djust

### Impact The djust live transport resolves the LiveView to mount from a **client-supplied dotted path** by calling `__import__(module_path, ...)`. The module is imported — running its **top-level code (import side effects)** — *before* the framework checks that the resolved object is a `LiveView` subclass and *before* any per-view authentication. The `LIVEVIEW_ALLOWED_MODULES` allowlist that should contain this is **fail-open** (`if allowed_modules:` — skipped when the setting is unset, the framework default) and uses loose `startswith` matching.

An **unauthenticated** WebSocket client (the WS handshake does not require auth; per-view auth runs only after import + instantiate) can therefore send a `mount` / `live_redirect_mount` / `url_change` frame (or an SSE mount) with `view = "<any.importable.module>.AnyName"` and cause the server to import — and execute the top-level code of — **any importable Python module by name**.

**Consequences:** server-side execution of arbitrary importable modules' import-time side effects by an unauthenticated client (effectively RCE-by-proxy on any host that has a side-effectful importable module), denial of service (import bombs / expensive dependency trees), and a module/class **enumeration oracle** via distinct error strings.

Reproduced end-to-end: an unauthenticated `WebsocketCommunicator` `mount` frame with the allowlist unset imported and executed a sentinel non-LiveView module before the "not a LiveView subclass" rejection.

### Af…