diff --git a/hermes_cli/env_loader.py b/hermes_cli/env_loader.py
index 66441058b9..7508f53c25 100644
--- a/hermes_cli/env_loader.py
+++ b/hermes_cli/env_loader.py
@@ -539,10 +539,31 @@ def _load_secrets_config(home_path: Path) -> dict:
 
 
 def _process_hermes_home() -> Path:
-    """The HERMES_HOME the shared config cache is keyed to."""
-    try:
-        from hermes_constants import get_hermes_home
+    """The HERMES_HOME the running process was launched under.
 
-        return get_hermes_home()
+    Must be the *true* process home, ignoring any context-local
+    ``set_hermes_home_override`` a per-request task has installed. Both
+    callers depend on that:
+
+    * ``_reapply_terminal_config_bridge`` guards "only re-bridge config into
+      the shared ``os.environ`` when THIS load is for the process's own
+      profile". If this followed the task override, a per-turn handler scoped
+      to a *secondary* profile (the multiplex dashboard serving every profile
+      from one process) would satisfy the guard and bridge that profile's
+      ``terminal.backend`` into the shared env — e.g. a ``local`` sibling
+      profile clobbering the launch profile's ``TERMINAL_ENV=ssh`` while
+      leaving its ``TERMINAL_SSH_*`` untouched, so the session silently runs
+      commands locally (cross-profile terminal-backend leak).
+    * ``_load_secrets_config`` uses it to decide whether the shared
+      (mtime,size)-keyed config cache is safe to reuse; under an override it
+      must fall through to an isolated parse of the scoped profile.
+
+    ``hermes_constants.get_process_hermes_home()`` is the override-immune
+    resolver built for exactly this; delegate to it.
+    """
+    try:
+        from hermes_constants import get_process_hermes_home
+
+        return get_process_hermes_home()
     except Exception:
         return Path.home() / ".hermes"
diff --git a/tests/hermes_cli/test_terminal_bridge_profile_scope.py b/tests/hermes_cli/test_terminal_bridge_profile_scope.py
new file mode 100644
index 0000000000..4dade567c7
--- /dev/null
+++ b/tests/hermes_cli/test_terminal_bridge_profile_scope.py
@@ -0,0 +1,93 @@
+"""Regression: the terminal config→env re-bridge is scoped to the *true*
+process profile, never a per-task ``set_hermes_home_override``.
+
+The multiplex dashboard serves every profile on the host from one process,
+so ``os.environ`` is shared across all of them. A per-turn handler scoped to
+a secondary profile (via ``set_hermes_home_override``) must NOT cause that
+profile's ``terminal.backend`` to be bridged into the shared environment —
+otherwise a ``local`` sibling profile silently clobbers the launch profile's
+``TERMINAL_ENV=ssh`` (leaving its ``TERMINAL_SSH_*`` intact), and the launch
+session runs every command locally instead of over SSH.
+
+The guard in ``env_loader._reapply_terminal_config_bridge`` compares the
+loaded home against the process home. It must use the override-immune
+``get_process_hermes_home()`` so the comparison reflects the launch scope,
+not whichever profile the current task is scoped to.
+"""
+
+import os
+
+import pytest
+
+import hermes_cli.env_loader as env_loader
+from hermes_constants import (
+    set_hermes_home_override,
+    reset_hermes_home_override,
+)
+
+
+def _write_terminal_config(home, text: str) -> None:
+    home.mkdir(parents=True, exist_ok=True)
+    (home / "config.yaml").write_text(text)
+
+
+@pytest.fixture(autouse=True)
+def _clean_terminal_env(monkeypatch):
+    for name in ("TERMINAL_ENV", "TERMINAL_SSH_HOST", "TERMINAL_SSH_USER"):
+        monkeypatch.delenv(name, raising=False)
+    yield
+
+
+def test_process_hermes_home_ignores_task_override(tmp_path, monkeypatch):
+    """The guard's home resolver must not follow a per-task override."""
+    launch_home = tmp_path / "laptop"
+    other_home = tmp_path / "tommy"
+    launch_home.mkdir()
+    other_home.mkdir()
+    monkeypatch.setenv("HERMES_HOME", str(launch_home))
+
+    token = set_hermes_home_override(str(other_home))
+    try:
+        assert (
+            env_loader._process_hermes_home().resolve() == launch_home.resolve()
+        ), "process home leaked to the per-task override profile"
+    finally:
+        reset_hermes_home_override(token)
+
+
+def test_secondary_profile_reload_does_not_bridge_into_shared_env(
+    tmp_path, monkeypatch
+):
+    """A secondary profile's terminal.backend must not touch os.environ.
+
+    Simulates the dashboard multiplex: process launched under ``laptop``
+    (ssh), a per-turn handler scoped to ``tommy`` (local) triggers a dotenv
+    reload for tommy's home. The launch session's TERMINAL_ENV must survive.
+    """
+    launch_home = tmp_path / "laptop"
+    other_home = tmp_path / "tommy"
+    _write_terminal_config(
+        launch_home,
+        "terminal:\n"
+        "  backend: ssh\n"
+        "  ssh_host: 10.10.0.103\n"
+        "  ssh_user: bergmann\n",
+    )
+    _write_terminal_config(other_home, "terminal:\n  backend: local\n")
+    monkeypatch.setenv("HERMES_HOME", str(launch_home))
+
+    # Launch profile's backend is what the shared env carries.
+    monkeypatch.setenv("TERMINAL_ENV", "ssh")
+    monkeypatch.setenv("TERMINAL_SSH_HOST", "10.10.0.103")
+
+    # A per-turn handler for the secondary profile is scoped via the contextvar
+    # and drives a reload for tommy's home.
+    token = set_hermes_home_override(str(other_home))
+    try:
+        env_loader._reapply_terminal_config_bridge(other_home)
+    finally:
+        reset_hermes_home_override(token)
+
+    # tommy's `local` must NOT have leaked into the shared process env.
+    assert os.environ["TERMINAL_ENV"] == "ssh"
+    assert os.environ["TERMINAL_SSH_HOST"] == "10.10.0.103"