diff --git a/tests/computer_use/test_cua_cli_fallback_env.py b/tests/computer_use/test_cua_cli_fallback_env.py
new file mode 100644
index 000000000..1f3180dfe
--- /dev/null
+++ b/tests/computer_use/test_cua_cli_fallback_env.py
@@ -0,0 +1,73 @@
+"""Regression test: the cua-driver CLI-fallback transport must sanitize the
+subprocess environment like every other cua-driver spawn site.
+
+``_CuaDriverSession._call_tool_via_cli()`` (the EAGAIN/silent-empty MCP
+fallback) invoked ``subprocess.run`` with no ``env=`` at all, so the
+third-party ``cua-driver`` binary inherited the full, unsanitized parent
+environment — including provider API keys and other Hermes-managed
+secrets that ``_lifecycle_coro``'s primary MCP spawn already strips via
+``_sanitize_subprocess_env(cua_driver_child_env())``.
+"""
+
+import json
+from unittest.mock import MagicMock
+
+from tools.computer_use.cua_backend import _CuaDriverSession
+
+
+def _make_session() -> _CuaDriverSession:
+    # _call_tool_via_cli() doesn't touch any instance state (bridge/session/
+    # capabilities); bypass __init__ so the test doesn't need a real
+    # _AsyncBridge.
+    return object.__new__(_CuaDriverSession)
+
+
+def _fake_completed_process(stdout: str) -> MagicMock:
+    proc = MagicMock()
+    proc.stdout = stdout
+    proc.stderr = ""
+    proc.returncode = 0
+    return proc
+
+
+def test_cli_fallback_strips_provider_secret_from_subprocess_env(monkeypatch):
+    monkeypatch.setenv("ANTHROPIC_API_KEY", "sk-super-secret-should-not-leak")
+    monkeypatch.setenv("PATH", "/usr/bin:/bin")
+
+    captured = {}
+
+    def fake_run(cmd, **kwargs):
+        captured["env"] = kwargs.get("env")
+        return _fake_completed_process(json.dumps({"tree_markdown": "root"}))
+
+    monkeypatch.setattr("subprocess.run", fake_run)
+
+    session = _make_session()
+    result = session._call_tool_via_cli("list_windows", {}, timeout=5.0)
+
+    assert result["isError"] is False
+    assert captured["env"] is not None, "subprocess.run must receive an explicit env="
+    assert "ANTHROPIC_API_KEY" not in captured["env"]
+    # Sanitization filters secrets, not everything — an ordinary var survives.
+    assert captured["env"].get("PATH") == "/usr/bin:/bin"
+
+
+def test_cli_fallback_applies_telemetry_policy(monkeypatch):
+    """The env should also go through cua_driver_child_env(), like every
+    other cua-driver spawn site, not just _sanitize_subprocess_env alone."""
+    monkeypatch.delenv("HERMES_CUA_TELEMETRY", raising=False)
+    captured = {}
+
+    def fake_run(cmd, **kwargs):
+        captured["env"] = kwargs.get("env")
+        return _fake_completed_process(json.dumps({"tree_markdown": "root"}))
+
+    monkeypatch.setattr("subprocess.run", fake_run)
+
+    session = _make_session()
+    session._call_tool_via_cli("list_windows", {}, timeout=5.0)
+
+    # cua_driver_child_env() injects this when telemetry is disabled
+    # (the default) — confirms the fallback goes through the same helper
+    # the sanctioned spawn site uses, not an ad hoc env dict.
+    assert captured["env"].get("CUA_DRIVER_RS_TELEMETRY_ENABLED") == "0"
diff --git a/tools/computer_use/cua_backend.py b/tools/computer_use/cua_backend.py
index 67f2add21..a2a9314ea 100644
--- a/tools/computer_use/cua_backend.py
+++ b/tools/computer_use/cua_backend.py
@@ -894,6 +894,7 @@ class _CuaDriverSession:
         import subprocess as _subprocess
         import tempfile as _tempfile
         import time as _time
+        from tools.environments.local import _sanitize_subprocess_env
 
         call_args = dict(args)
         shot_file: Optional[str] = None
@@ -911,7 +912,8 @@ class _CuaDriverSession:
             for attempt in range(attempts):
                 try:
                     proc = _subprocess.run(
-                        cmd, capture_output=True, text=True, timeout=max(15.0, timeout)
+                        cmd, capture_output=True, text=True, timeout=max(15.0, timeout),
+                        env=_sanitize_subprocess_env(cua_driver_child_env()),
                     )
                 except Exception as e:  # pragma: no cover - subprocess spawn failure
                     raise RuntimeError(f"cua-driver CLI fallback for {name} failed to spawn: {e}") from e