diff --git a/src/flask/app.py b/src/flask/app.py
index 736061b9..084429aa 100644
--- a/src/flask/app.py
+++ b/src/flask/app.py
@@ -38,10 +38,11 @@ from .config import ConfigAttribute
 from .ctx import _AppCtxGlobals
 from .ctx import AppContext
 from .ctx import RequestContext
-from .globals import _app_ctx_stack
-from .globals import _request_ctx_stack
+from .globals import _cv_app
+from .globals import _cv_req
 from .globals import g
 from .globals import request
+from .globals import request_ctx
 from .globals import session
 from .helpers import _split_blueprint_path
 from .helpers import get_debug_flag
@@ -1554,10 +1555,10 @@ class Flask(Scaffold):
            This no longer does the exception handling, this code was
            moved to the new :meth:`full_dispatch_request`.
         """
-        req = _request_ctx_stack.top.request
+        req = request_ctx.request
         if req.routing_exception is not None:
             self.raise_routing_exception(req)
-        rule = req.url_rule
+        rule: Rule = req.url_rule  # type: ignore[assignment]
         # if we provide automatic options for this URL and the
         # request came with the OPTIONS method, reply automatically
         if (
@@ -1566,7 +1567,8 @@ class Flask(Scaffold):
         ):
             return self.make_default_options_response()
         # otherwise dispatch to the handler for that endpoint
-        return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
+        view_args: t.Dict[str, t.Any] = req.view_args  # type: ignore[assignment]
+        return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
 
     def full_dispatch_request(self) -> Response:
         """Dispatches the request and on top of that performs request
@@ -1631,8 +1633,8 @@ class Flask(Scaffold):
 
         .. versionadded:: 0.7
         """
-        adapter = _request_ctx_stack.top.url_adapter
-        methods = adapter.allowed_methods()
+        adapter = request_ctx.url_adapter
+        methods = adapter.allowed_methods()  # type: ignore[union-attr]
         rv = self.response_class()
         rv.allow.update(methods)
         return rv
@@ -1740,7 +1742,7 @@ class Flask(Scaffold):
         .. versionadded:: 2.2
             Moved from ``flask.url_for``, which calls this method.
         """
-        req_ctx = _request_ctx_stack.top
+        req_ctx = _cv_req.get(None)
 
         if req_ctx is not None:
             url_adapter = req_ctx.url_adapter
@@ -1759,7 +1761,7 @@ class Flask(Scaffold):
             if _external is None:
                 _external = _scheme is not None
         else:
-            app_ctx = _app_ctx_stack.top
+            app_ctx = _cv_app.get(None)
 
             # If called by helpers.url_for, an app context is active,
             # use its url_adapter. Otherwise, app.url_for was called
@@ -1790,7 +1792,7 @@ class Flask(Scaffold):
         self.inject_url_defaults(endpoint, values)
 
         try:
-            rv = url_adapter.build(
+            rv = url_adapter.build(  # type: ignore[union-attr]
                 endpoint,
                 values,
                 method=_method,
@@ -2099,7 +2101,7 @@ class Flask(Scaffold):
         :return: a new response object or the same, has to be an
                  instance of :attr:`response_class`.
         """
-        ctx = _request_ctx_stack.top
+        ctx = request_ctx._get_current_object()  # type: ignore[attr-defined]
 
         for func in ctx._after_request_functions:
             response = self.ensure_sync(func)(response)
@@ -2305,8 +2307,8 @@ class Flask(Scaffold):
             return response(environ, start_response)
         finally:
             if "werkzeug.debug.preserve_context" in environ:
-                environ["werkzeug.debug.preserve_context"](_app_ctx_stack.top)
-                environ["werkzeug.debug.preserve_context"](_request_ctx_stack.top)
+                environ["werkzeug.debug.preserve_context"](_cv_app.get())
+                environ["werkzeug.debug.preserve_context"](_cv_req.get())
 
             if error is not None and self.should_ignore_error(error):
                 error = None
diff --git a/src/flask/cli.py b/src/flask/cli.py
index af29b2c1..ba0db467 100644
--- a/src/flask/cli.py
+++ b/src/flask/cli.py
@@ -1051,13 +1051,11 @@ def shell_command() -> None:
     without having to manually configure the application.
     """
     import code
-    from .globals import _app_ctx_stack
 
-    app = _app_ctx_stack.top.app
     banner = (
         f"Python {sys.version} on {sys.platform}\n"
-        f"App: {app.import_name} [{app.env}]\n"
-        f"Instance: {app.instance_path}"
+        f"App: {current_app.import_name} [{current_app.env}]\n"
+        f"Instance: {current_app.instance_path}"
     )
     ctx: dict = {}
 
@@ -1068,7 +1066,7 @@ def shell_command() -> None:
         with open(startup) as f:
             eval(compile(f.read(), startup, "exec"), ctx)
 
-    ctx.update(app.make_shell_context())
+    ctx.update(current_app.make_shell_context())
 
     # Site, customize, or startup script can set a hook to call when
     # entering interactive mode. The default one sets up readline with
diff --git a/src/flask/ctx.py b/src/flask/ctx.py
index 758127ea..62242e80 100644
--- a/src/flask/ctx.py
+++ b/src/flask/ctx.py
@@ -7,10 +7,8 @@ from types import TracebackType
 from werkzeug.exceptions import HTTPException
 
 from . import typing as ft
-from .globals import _app_ctx_stack
 from .globals import _cv_app
 from .globals import _cv_req
-from .globals import _request_ctx_stack
 from .signals import appcontext_popped
 from .signals import appcontext_pushed
 
@@ -106,9 +104,9 @@ class _AppCtxGlobals:
         return iter(self.__dict__)
 
     def __repr__(self) -> str:
-        top = _app_ctx_stack.top
-        if top is not None:
-            return f"<flask.g of {top.app.name!r}>"
+        ctx = _cv_app.get(None)
+        if ctx is not None:
+            return f"<flask.g of '{ctx.app.name}'>"
         return object.__repr__(self)
 
 
@@ -133,15 +131,15 @@ def after_this_request(f: ft.AfterRequestCallable) -> ft.AfterRequestCallable:
 
     .. versionadded:: 0.9
     """
-    top = _request_ctx_stack.top
+    ctx = _cv_req.get(None)
 
-    if top is None:
+    if ctx is None:
         raise RuntimeError(
-            "This decorator can only be used when a request context is"
-            " active, such as within a view function."
+            "'after_this_request' can only be used when a request"
+            " context is active, such as in a view function."
         )
 
-    top._after_request_functions.append(f)
+    ctx._after_request_functions.append(f)
     return f
 
 
@@ -169,19 +167,19 @@ def copy_current_request_context(f: t.Callable) -> t.Callable:
 
     .. versionadded:: 0.10
     """
-    top = _request_ctx_stack.top
+    ctx = _cv_req.get(None)
 
-    if top is None:
+    if ctx is None:
         raise RuntimeError(
-            "This decorator can only be used when a request context is"
-            " active, such as within a view function."
+            "'copy_current_request_context' can only be used when a"
+            " request context is active, such as in a view function."
         )
 
-    reqctx = top.copy()
+    ctx = ctx.copy()
 
     def wrapper(*args, **kwargs):
-        with reqctx:
-            return reqctx.app.ensure_sync(f)(*args, **kwargs)
+        with ctx:
+            return ctx.app.ensure_sync(f)(*args, **kwargs)
 
     return update_wrapper(wrapper, f)
 
@@ -240,7 +238,7 @@ class AppContext:
     def __init__(self, app: "Flask") -> None:
         self.app = app
         self.url_adapter = app.create_url_adapter(None)
-        self.g = app.app_ctx_globals_class()
+        self.g: _AppCtxGlobals = app.app_ctx_globals_class()
         self._cv_tokens: t.List[contextvars.Token] = []
 
     def push(self) -> None:
@@ -311,14 +309,14 @@ class RequestContext:
         self.app = app
         if request is None:
             request = app.request_class(environ)
-        self.request = request
+        self.request: Request = request
         self.url_adapter = None
         try:
             self.url_adapter = app.create_url_adapter(self.request)
         except HTTPException as e:
             self.request.routing_exception = e
-        self.flashes = None
-        self.session = session
+        self.flashes: t.Optional[t.List[t.Tuple[str, str]]] = None
+        self.session: t.Optional["SessionMixin"] = session
         # Functions that should be executed after the request on the response
         # object.  These will be called before the regular "after_request"
         # functions.
diff --git a/src/flask/debughelpers.py b/src/flask/debughelpers.py
index b1e3ce1b..b0639892 100644
--- a/src/flask/debughelpers.py
+++ b/src/flask/debughelpers.py
@@ -2,7 +2,7 @@ import typing as t
 
 from .app import Flask
 from .blueprints import Blueprint
-from .globals import _request_ctx_stack
+from .globals import request_ctx
 
 
 class UnexpectedUnicodeError(AssertionError, UnicodeError):
@@ -116,9 +116,8 @@ def explain_template_loading_attempts(app: Flask, template, attempts) -> None:
     info = [f"Locating template {template!r}:"]
     total_found = 0
     blueprint = None
-    reqctx = _request_ctx_stack.top
-    if reqctx is not None and reqctx.request.blueprint is not None:
-        blueprint = reqctx.request.blueprint
+    if request_ctx and request_ctx.request.blueprint is not None:
+        blueprint = request_ctx.request.blueprint
 
     for idx, (loader, srcobj, triple) in enumerate(attempts):
         if isinstance(srcobj, Flask):
diff --git a/src/flask/helpers.py b/src/flask/helpers.py
index 79c562c0..bc074b6a 100644
--- a/src/flask/helpers.py
+++ b/src/flask/helpers.py
@@ -12,9 +12,10 @@ import werkzeug.utils
 from werkzeug.exceptions import abort as _wz_abort
 from werkzeug.utils import redirect as _wz_redirect
 
-from .globals import _request_ctx_stack
+from .globals import _cv_req
 from .globals import current_app
 from .globals import request
+from .globals import request_ctx
 from .globals import session
 from .signals import message_flashed
 
@@ -110,11 +111,11 @@ def stream_with_context(
         return update_wrapper(decorator, generator_or_function)  # type: ignore
 
     def generator() -> t.Generator:
-        ctx = _request_ctx_stack.top
+        ctx = _cv_req.get(None)
         if ctx is None:
             raise RuntimeError(
-                "Attempted to stream with context but "
-                "there was no context in the first place to keep around."
+                "'stream_with_context' can only be used when a request"
+                " context is active, such as in a view function."
             )
         with ctx:
             # Dummy sentinel.  Has to be inside the context block or we're
@@ -377,11 +378,10 @@ def get_flashed_messages(
     :param category_filter: filter of categories to limit return values.  Only
                             categories in the list will be returned.
     """
-    flashes = _request_ctx_stack.top.flashes
+    flashes = request_ctx.flashes
     if flashes is None:
-        _request_ctx_stack.top.flashes = flashes = (
-            session.pop("_flashes") if "_flashes" in session else []
-        )
+        flashes = session.pop("_flashes") if "_flashes" in session else []
+        request_ctx.flashes = flashes
     if category_filter:
         flashes = list(filter(lambda f: f[0] in category_filter, flashes))
     if not with_categories:
diff --git a/src/flask/templating.py b/src/flask/templating.py
index 7d92cf1e..24a672b7 100644
--- a/src/flask/templating.py
+++ b/src/flask/templating.py
@@ -5,8 +5,8 @@ from jinja2 import Environment as BaseEnvironment
 from jinja2 import Template
 from jinja2 import TemplateNotFound
 
-from .globals import _app_ctx_stack
-from .globals import _request_ctx_stack
+from .globals import _cv_app
+from .globals import _cv_req
 from .globals import current_app
 from .globals import request
 from .helpers import stream_with_context
@@ -22,9 +22,9 @@ def _default_template_ctx_processor() -> t.Dict[str, t.Any]:
     """Default template context processor.  Injects `request`,
     `session` and `g`.
     """
-    reqctx = _request_ctx_stack.top
-    appctx = _app_ctx_stack.top
-    rv = {}
+    appctx = _cv_app.get(None)
+    reqctx = _cv_req.get(None)
+    rv: t.Dict[str, t.Any] = {}
     if appctx is not None:
         rv["g"] = appctx.g
     if reqctx is not None:
@@ -124,7 +124,8 @@ class DispatchingJinjaLoader(BaseLoader):
         return list(result)
 
 
-def _render(template: Template, context: dict, app: "Flask") -> str:
+def _render(app: "Flask", template: Template, context: t.Dict[str, t.Any]) -> str:
+    app.update_template_context(context)
     before_render_template.send(app, template=template, context=context)
     rv = template.render(context)
     template_rendered.send(app, template=template, context=context)
@@ -135,36 +136,27 @@ def render_template(
     template_name_or_list: t.Union[str, Template, t.List[t.Union[str, Template]]],
     **context: t.Any
 ) -> str:
-    """Renders a template from the template folder with the given
-    context.
+    """Render a template by name with the given context.
 
-    :param template_name_or_list: the name of the template to be
-                                  rendered, or an iterable with template names
-                                  the first one existing will be rendered
-    :param context: the variables that should be available in the
-                    context of the template.
+    :param template_name_or_list: The name of the template to render. If
+        a list is given, the first name to exist will be rendered.
+    :param context: The variables to make available in the template.
     """
-    ctx = _app_ctx_stack.top
-    ctx.app.update_template_context(context)
-    return _render(
-        ctx.app.jinja_env.get_or_select_template(template_name_or_list),
-        context,
-        ctx.app,
-    )
+    app = current_app._get_current_object()  # type: ignore[attr-defined]
+    template = app.jinja_env.get_or_select_template(template_name_or_list)
+    return _render(app, template, context)
 
 
 def render_template_string(source: str, **context: t.Any) -> str:
-    """Renders a template from the given template source string
-    with the given context. Template variables will be autoescaped.
+    """Render a template from the given source string with the given
+    context.
 
-    :param source: the source code of the template to be
-                   rendered
-    :param context: the variables that should be available in the
-                    context of the template.
+    :param source: The source code of the template to render.
+    :param context: The variables to make available in the template.
     """
-    ctx = _app_ctx_stack.top
-    ctx.app.update_template_context(context)
-    return _render(ctx.app.jinja_env.from_string(source), context, ctx.app)
+    app = current_app._get_current_object()  # type: ignore[attr-defined]
+    template = app.jinja_env.from_string(source)
+    return _render(app, template, context)
 
 
 def _stream(
diff --git a/src/flask/testing.py b/src/flask/testing.py
index 0e1189c9..e188439b 100644
--- a/src/flask/testing.py
+++ b/src/flask/testing.py
@@ -163,7 +163,7 @@ class FlaskClient(Client):
             # behavior.  It's important to not use the push and pop
             # methods of the actual request context object since that would
             # mean that cleanup handlers are called
-            token = _cv_req.set(outer_reqctx)
+            token = _cv_req.set(outer_reqctx)  # type: ignore[arg-type]
             try:
                 yield sess
             finally:
diff --git a/tests/conftest.py b/tests/conftest.py
index 1e1ba0d4..670acc88 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -6,8 +6,8 @@ import textwrap
 import pytest
 from _pytest import monkeypatch
 
-import flask
-from flask import Flask as _Flask
+from flask import Flask
+from flask.globals import request_ctx
 
 
 @pytest.fixture(scope="session", autouse=True)
@@ -44,14 +44,13 @@ def _reset_os_environ(monkeypatch, _standard_os_environ):
     monkeypatch._setitem.extend(_standard_os_environ)
 
 
-class Flask(_Flask):
-    testing = True
-    secret_key = "test key"
-
-
 @pytest.fixture
 def app():
     app = Flask("flask_test", root_path=os.path.dirname(__file__))
+    app.config.update(
+        TESTING=True,
+        SECRET_KEY="test key",
+    )
     return app
 
 
@@ -92,8 +91,10 @@ def leak_detector():
     # make sure we're not leaking a request context since we are
     # testing flask internally in debug mode in a few cases
     leaks = []
-    while flask._request_ctx_stack.top is not None:
-        leaks.append(flask._request_ctx_stack.pop())
+    while request_ctx:
+        leaks.append(request_ctx._get_current_object())
+        request_ctx.pop()
+
     assert leaks == []
 
 
diff --git a/tests/test_appctx.py b/tests/test_appctx.py
index aeb75a55..f5ca0bde 100644
--- a/tests/test_appctx.py
+++ b/tests/test_appctx.py
@@ -1,6 +1,8 @@
 import pytest
 
 import flask
+from flask.globals import app_ctx
+from flask.globals import request_ctx
 
 
 def test_basic_url_generation(app):
@@ -29,14 +31,14 @@ def test_url_generation_without_context_fails():
 
 def test_request_context_means_app_context(app):
     with app.test_request_context():
-        assert flask.current_app._get_current_object() == app
-    assert flask._app_ctx_stack.top is None
+        assert flask.current_app._get_current_object() is app
+    assert not flask.current_app
 
 
 def test_app_context_provides_current_app(app):
     with app.app_context():
-        assert flask.current_app._get_current_object() == app
-    assert flask._app_ctx_stack.top is None
+        assert flask.current_app._get_current_object() is app
+    assert not flask.current_app
 
 
 def test_app_tearing_down(app):
@@ -175,11 +177,11 @@ def test_context_refcounts(app, client):
 
     @app.route("/")
     def index():
-        with flask._app_ctx_stack.top:
-            with flask._request_ctx_stack.top:
+        with app_ctx:
+            with request_ctx:
                 pass
-        env = flask._request_ctx_stack.top.request.environ
-        assert env["werkzeug.request"] is not None
+
+        assert flask.request.environ["werkzeug.request"] is not None
         return ""
 
     res = client.get("/")
diff --git a/tests/test_basic.py b/tests/test_basic.py
index dca48e2d..3e98fdac 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -1110,14 +1110,10 @@ def test_enctype_debug_helper(app, client):
     def index():
         return flask.request.files["foo"].filename
 
-    # with statement is important because we leave an exception on the
-    # stack otherwise and we want to ensure that this is not the case
-    # to not negatively affect other tests.
-    with client:
-        with pytest.raises(DebugFilesKeyError) as e:
-            client.post("/fail", data={"foo": "index.txt"})
-        assert "no file contents were transmitted" in str(e.value)
-        assert "This was submitted: 'index.txt'" in str(e.value)
+    with pytest.raises(DebugFilesKeyError) as e:
+        client.post("/fail", data={"foo": "index.txt"})
+    assert "no file contents were transmitted" in str(e.value)
+    assert "This was submitted: 'index.txt'" in str(e.value)
 
 
 def test_response_types(app, client):
@@ -1548,29 +1544,21 @@ def test_server_name_subdomain():
     assert rv.data == b"subdomain"
 
 
-@pytest.mark.filterwarnings("ignore::pytest.PytestUnraisableExceptionWarning")
-@pytest.mark.filterwarnings("ignore::pytest.PytestUnhandledThreadExceptionWarning")
-def test_exception_propagation(app, client):
-    def apprunner(config_key):
-        @app.route("/")
-        def index():
-            1 // 0
+@pytest.mark.parametrize("key", ["TESTING", "PROPAGATE_EXCEPTIONS", "DEBUG", None])
+def test_exception_propagation(app, client, key):
+    app.testing = False
 
-        if config_key is not None:
-            app.config[config_key] = True
-            with pytest.raises(Exception):
-                client.get("/")
-        else:
-            assert client.get("/").status_code == 500
+    @app.route("/")
+    def index():
+        1 // 0
 
-    # we have to run this test in an isolated thread because if the
-    # debug flag is set to true and an exception happens the context is
-    # not torn down.  This causes other tests that run after this fail
-    # when they expect no exception on the stack.
-    for config_key in "TESTING", "PROPAGATE_EXCEPTIONS", "DEBUG", None:
-        t = Thread(target=apprunner, args=(config_key,))
-        t.start()
-        t.join()
+    if key is not None:
+        app.config[key] = True
+
+        with pytest.raises(ZeroDivisionError):
+            client.get("/")
+    else:
+        assert client.get("/").status_code == 500
 
 
 @pytest.mark.parametrize("debug", [True, False])
diff --git a/tests/test_reqctx.py b/tests/test_reqctx.py
index 1a478917..abfacb98 100644
--- a/tests/test_reqctx.py
+++ b/tests/test_reqctx.py
@@ -3,6 +3,7 @@ import warnings
 import pytest
 
 import flask
+from flask.globals import request_ctx
 from flask.sessions import SecureCookieSessionInterface
 from flask.sessions import SessionInterface
 
@@ -116,7 +117,7 @@ def test_context_binding(app):
         assert index() == "Hello World!"
     with app.test_request_context("/meh"):
         assert meh() == "http://localhost/meh"
-    assert flask._request_ctx_stack.top is None
+    assert not flask.request
 
 
 def test_context_test(app):
@@ -152,7 +153,7 @@ class TestGreenletContextCopying:
         @app.route("/")
         def index():
             flask.session["fizz"] = "buzz"
-            reqctx = flask._request_ctx_stack.top.copy()
+            reqctx = request_ctx.copy()
 
             def g():
                 assert not flask.request
diff --git a/tests/test_session_interface.py b/tests/test_session_interface.py
index 39562f5a..613da37f 100644
--- a/tests/test_session_interface.py
+++ b/tests/test_session_interface.py
@@ -1,4 +1,5 @@
 import flask
+from flask.globals import request_ctx
 from flask.sessions import SessionInterface
 
 
@@ -13,7 +14,7 @@ def test_open_session_with_endpoint():
             pass
 
         def open_session(self, app, request):
-            flask._request_ctx_stack.top.match_request()
+            request_ctx.match_request()
             assert request.endpoint is not None
 
     app = flask.Flask(__name__)
diff --git a/tests/test_testing.py b/tests/test_testing.py
index dd6347e5..0b37a2e5 100644
--- a/tests/test_testing.py
+++ b/tests/test_testing.py
@@ -5,6 +5,7 @@ import werkzeug
 import flask
 from flask import appcontext_popped
 from flask.cli import ScriptInfo
+from flask.globals import _cv_req
 from flask.json import jsonify
 from flask.testing import EnvironBuilder
 from flask.testing import FlaskCliRunner
@@ -399,4 +400,4 @@ def test_client_pop_all_preserved(app, req_ctx, client):
     # close the response, releasing the context held by stream_with_context
     rv.close()
     # only req_ctx fixture should still be pushed
-    assert flask._request_ctx_stack.top is req_ctx
+    assert _cv_req.get(None) is req_ctx