diff --git a/hermes_cli/web_routers/git.py b/hermes_cli/web_routers/git.py
index a8bbe0ea5d..f24f839909 100644
--- a/hermes_cli/web_routers/git.py
+++ b/hermes_cli/web_routers/git.py
@@ -15,6 +15,7 @@ from typing import Optional
 from fastapi import APIRouter, HTTPException
 
 from hermes_cli import web_git as _web_git
+from hermes_cli._subprocess_compat import bounded_probe_run
 from hermes_cli.web_deps import late
 from hermes_cli.web_server_files import _fs_path
 from hermes_cli.web_models import (
@@ -56,6 +57,7 @@ async def git_status_route(path: str):
 # only to users who aren't already authenticated.
 _GH_AUTH_TTL_S = 300.0
 _gh_auth_cache: Optional[tuple] = None  # (monotonic_ts, payload)
+_gh_auth_probe_task: Optional[asyncio.Task] = None
 
 
 def _probe_gh_auth() -> dict:
@@ -64,25 +66,33 @@ def _probe_gh_auth() -> dict:
         return {"available": False, "authenticated": False}
     try:
         # Exits 0 when at least one host is logged in; DEVNULL stdin guards against any prompt.
-        proc = subprocess.run(
-            [gh, "auth", "status"],
-            stdin=subprocess.DEVNULL,
-            capture_output=True,
-            timeout=10,
-        )
-        return {"available": True, "authenticated": proc.returncode == 0}
+        proc = bounded_probe_run([gh, "auth", "status"], timeout=10)
+        return {"available": True, "authenticated": bool(proc and proc.returncode == 0)}
     except Exception:
         return {"available": True, "authenticated": False}
 
 
+def _clear_gh_auth_probe_task(completed_task: asyncio.Task) -> None:
+    """Release a completed shared probe even if all requesters disconnected."""
+    global _gh_auth_probe_task
+    if _gh_auth_probe_task is completed_task:
+        _gh_auth_probe_task = None
+
+
 @router.get("/api/git/gh-auth")
 async def gh_auth_status_route(refresh: bool = False):
     """``{"available", "authenticated"}`` for the `gh` CLI; cached 5 min
     (``refresh=true`` bypasses so the pill withdraws right after a login)."""
-    global _gh_auth_cache
+    global _gh_auth_cache, _gh_auth_probe_task
     if not refresh and _gh_auth_cache and time.monotonic() - _gh_auth_cache[0] < _GH_AUTH_TTL_S:
         return _gh_auth_cache[1]
-    payload = await asyncio.to_thread(_probe_gh_auth)
+    if _gh_auth_probe_task is None:
+        _gh_auth_probe_task = asyncio.create_task(asyncio.to_thread(_probe_gh_auth))
+        _gh_auth_probe_task.add_done_callback(_clear_gh_auth_probe_task)
+    probe_task = _gh_auth_probe_task
+    # Shield the shared probe: disconnecting one requester must not cancel the
+    # probe that other refreshes/cache misses are awaiting.
+    payload = await asyncio.shield(probe_task)
     _gh_auth_cache = (time.monotonic(), payload)
     return payload
 
diff --git a/tests/hermes_cli/test_web_server_git.py b/tests/hermes_cli/test_web_server_git.py
index 752f76e74d..8e4164e523 100644
--- a/tests/hermes_cli/test_web_server_git.py
+++ b/tests/hermes_cli/test_web_server_git.py
@@ -1,14 +1,88 @@
+import asyncio
 import subprocess
+import threading
 from pathlib import Path
 
 import pytest
 
 from hermes_cli import web_server
+from hermes_cli.web_routers import git as git_router
 
 pytest.importorskip("starlette.testclient")
 from starlette.testclient import TestClient
 
 
+@pytest.fixture(autouse=True)
+def reset_gh_auth_probe_state():
+    previous_cache = git_router._gh_auth_cache
+    previous_task = git_router._gh_auth_probe_task
+    git_router._gh_auth_cache = None
+    git_router._gh_auth_probe_task = None
+    try:
+        yield
+    finally:
+        git_router._gh_auth_cache = previous_cache
+        git_router._gh_auth_probe_task = previous_task
+
+
+def test_gh_auth_probe_uses_bounded_process_probe(monkeypatch):
+    monkeypatch.setattr(git_router.shutil, "which", lambda _: "/usr/bin/gh")
+    calls = []
+
+    def bounded(argv, *, timeout):
+        calls.append((argv, timeout))
+        return None  # The bounded helper returns None after timeout/tree cleanup.
+
+    monkeypatch.setattr(git_router, "bounded_probe_run", bounded)
+
+    assert git_router._probe_gh_auth() == {"available": True, "authenticated": False}
+    assert calls == [(["/usr/bin/gh", "auth", "status"], 10)]
+
+
+def test_gh_auth_concurrent_refreshes_share_one_probe(monkeypatch):
+    started = threading.Event()
+    release = threading.Event()
+    calls = 0
+
+    def probe():
+        nonlocal calls
+        calls += 1
+        started.set()
+        assert release.wait(timeout=1)
+        return {"available": True, "authenticated": True}
+
+    monkeypatch.setattr(git_router, "_probe_gh_auth", probe)
+
+    async def exercise():
+        first = asyncio.create_task(git_router.gh_auth_status_route(refresh=True))
+        while not started.is_set():
+            await asyncio.sleep(0)
+        second = asyncio.create_task(git_router.gh_auth_status_route(refresh=True))
+        await asyncio.sleep(0)
+        assert calls == 1
+        release.set()
+        return await asyncio.gather(first, second)
+
+    assert asyncio.run(exercise()) == [
+        {"available": True, "authenticated": True},
+        {"available": True, "authenticated": True},
+    ]
+    assert calls == 1
+
+
+def test_gh_auth_returns_fresh_cache_without_probing(monkeypatch):
+    git_router._gh_auth_cache = (git_router.time.monotonic(), {"available": True, "authenticated": True})
+    monkeypatch.setattr(git_router, "_probe_gh_auth", lambda: pytest.fail("cache miss"))
+
+    assert asyncio.run(git_router.gh_auth_status_route()) == {"available": True, "authenticated": True}
+
+
+def test_gh_auth_reports_unavailable_when_gh_is_missing(monkeypatch):
+    monkeypatch.setattr(git_router.shutil, "which", lambda _: None)
+
+    assert git_router._probe_gh_auth() == {"available": False, "authenticated": False}
+
+
 @pytest.fixture
 def client():
     previous = getattr(web_server.app.state, "auth_required", None)