fix(security): isolate multiplex dotenv reloads

hermes_cli/env_loader.py

@@ -483,10 +483,32 @@ def load_hermes_dotenv(
     - callers that only maintain the installation can set
       ``load_external_secrets=False`` to avoid loading optional secret-manager
       dependencies into the process that replaces that same environment.
+    - routed multiplex profile loads hydrate external sources into the
+      profile's private secret snapshot without mutating the shared process
+      environment; unscoped startup loads retain the normal behavior above.
     """
-    loaded: list[Path] = []
-
     home_path = Path(hermes_home or os.getenv("HERMES_HOME", Path.home() / ".hermes"))
+
+    # A multiplex gateway hosts every profile in one process.  While a routed
+    # profile-home override is active, copying that profile's .env into
+    # os.environ would expose its credentials to sibling turns and every
+    # subsequently spawned child.  An unscoped startup load remains process
+    # configuration and must retain the normal loading path.
+    # External secret sources still need their normal refresh path, so resolve
+    # them against the existing profile-local mapping instead of simply
+    # returning before all hydration work.
+    from agent.secret_scope import is_multiplex_active
+    from hermes_constants import get_hermes_home_override
+
+    if is_multiplex_active() and get_hermes_home_override() is not None:
+        if load_external_secrets:
+            from hermes_cli import _early_recovery
+
+            if not _early_recovery._should_skip_external_secret_sources():
+                hydrate_profile_secret_sources(home_path)
+        return []
+
+    loaded: list[Path] = []
     user_env = home_path / ".env"
     project_env_path = Path(project_env) if project_env else None
 

tests/gateway/test_multiplex_credential_isolation.py

@@ -88,6 +88,54 @@ class TestProfilePathResolutionUnderMultiplexScope:
         assert b_seen == prof_b / "skills"
 
 
+def test_turn_scoped_dotenv_reload_does_not_pollute_process_env(tmp_path, monkeypatch):
+    """A routed profile reload must stay inside its context-local scope.
+
+    ``load_hermes_dotenv`` has several lazy-import and cron call sites beyond
+    the gateway's guarded reload helper.  Any one of them can run during a
+    multiplexed turn, so the loader itself must not copy the active profile's
+    ``.env`` into the shared process environment.
+    """
+    import os
+
+    from agent.secret_scope import get_secret
+    from gateway.run import _profile_runtime_scope
+    from hermes_cli.env_loader import load_hermes_dotenv
+    from hermes_constants import get_hermes_home
+
+    profile_a = tmp_path / "profiles" / "a"
+    profile_b = tmp_path / "profiles" / "b"
+    profile_a.mkdir(parents=True)
+    profile_b.mkdir(parents=True)
+    (profile_a / ".env").write_text(
+        "PROFILE_SCOPED_API_KEY=secret-a\n"
+        "DISCORD_ALLOWED_CHANNELS=profile-a-only\n",
+        encoding="utf-8",
+    )
+    (profile_b / ".env").write_text(
+        "PROFILE_SCOPED_API_KEY=secret-b\n"
+        "DISCORD_ALLOWED_CHANNELS=profile-b-only\n",
+        encoding="utf-8",
+    )
+    monkeypatch.delenv("PROFILE_SCOPED_API_KEY", raising=False)
+    monkeypatch.setenv("DISCORD_ALLOWED_CHANNELS", "all-channels")
+
+    ss.set_multiplex_active(True)
+    with _profile_runtime_scope(profile_a):
+        assert get_secret("PROFILE_SCOPED_API_KEY") == "secret-a"
+        assert get_secret("DISCORD_ALLOWED_CHANNELS") == "profile-a-only"
+        assert load_hermes_dotenv(hermes_home=get_hermes_home()) == []
+        assert "PROFILE_SCOPED_API_KEY" not in os.environ
+        assert os.environ["DISCORD_ALLOWED_CHANNELS"] == "all-channels"
+
+    with _profile_runtime_scope(profile_b):
+        assert get_secret("PROFILE_SCOPED_API_KEY") == "secret-b"
+        assert get_secret("DISCORD_ALLOWED_CHANNELS") == "profile-b-only"
+        assert load_hermes_dotenv(hermes_home=get_hermes_home()) == []
+        assert "PROFILE_SCOPED_API_KEY" not in os.environ
+        assert os.environ["DISCORD_ALLOWED_CHANNELS"] == "all-channels"
+
+
 def test_cold_profile_hydrates_external_source_without_global_env(
     tmp_path, monkeypatch
 ):
@@ -164,5 +212,3 @@ def test_cold_profile_hydrates_external_source_without_global_env(
     assert calls["count"] == 1
     assert "TEST_PROVIDER_API_KEY" not in os.environ
     assert "EXPLICIT_API_KEY" not in os.environ
-
-

tests/test_env_loader_secret_sources.py

@@ -174,6 +174,55 @@ def test_cold_profile_bitwarden_uses_profile_bootstrap_without_global_env(
     assert os.environ.get("ANTHROPIC_API_KEY") is None
 
 
+def test_multiplex_dotenv_load_hydrates_sources_without_global_env(
+    tmp_path, monkeypatch
+):
+    """The safe multiplex path must still refresh profile secret sources."""
+    from agent import secret_scope
+    import agent.secret_sources.bitwarden as bw_module
+    from agent.secret_sources import registry as reg_module
+    from hermes_constants import (
+        reset_hermes_home_override,
+        set_hermes_home_override,
+    )
+
+    monkeypatch.delenv("BWS_ACCESS_TOKEN", raising=False)
+    monkeypatch.delenv("ANTHROPIC_API_KEY", raising=False)
+    (tmp_path / ".env").write_text(
+        "BWS_ACCESS_TOKEN=profile-bootstrap\n", encoding="utf-8"
+    )
+    (tmp_path / "config.yaml").write_text(
+        "secrets:\n"
+        "  bitwarden:\n"
+        "    enabled: true\n"
+        "    project_id: test-project\n"
+        "    access_token_env: BWS_ACCESS_TOKEN\n",
+        encoding="utf-8",
+    )
+    monkeypatch.setattr(bw_module, "find_bws", lambda **_kw: Path("/fake/bws"))
+    monkeypatch.setattr(
+        bw_module,
+        "fetch_bitwarden_secrets",
+        lambda **_kw: ({"ANTHROPIC_API_KEY": "profile-provider-key"}, []),
+    )
+    reg_module._reset_registry_for_tests()
+
+    was_active = secret_scope.is_multiplex_active()
+    home_token = set_hermes_home_override(tmp_path)
+    secret_scope.set_multiplex_active(True)
+    try:
+        assert env_loader.load_hermes_dotenv(hermes_home=tmp_path) == []
+    finally:
+        secret_scope.set_multiplex_active(was_active)
+        reset_hermes_home_override(home_token)
+
+    assert env_loader.get_secret_source_values(tmp_path) == {
+        "ANTHROPIC_API_KEY": "profile-provider-key"
+    }
+    assert os.environ.get("BWS_ACCESS_TOKEN") is None
+    assert os.environ.get("ANTHROPIC_API_KEY") is None
+
+
 def test_cold_profile_hydration_seeds_op_env_bootstrap(tmp_path, monkeypatch):
     """The .op.env bootstrap file must feed cold-profile hydration.