diff --git a/Lib/test/test_os/test_windows.py b/Lib/test/test_os/test_windows.py
index b21dd8a4dca6609..5f949d86610134b 100644
--- a/Lib/test/test_os/test_windows.py
+++ b/Lib/test/test_os/test_windows.py
@@ -608,5 +608,43 @@ def cleanup():
         self.assertGreaterEqual(stat1.st_atime, stat2.st_atime)
 
 
+class Win32StatExecutableTests(unittest.TestCase):
+    # gh-84419: Windows strips trailing dots and spaces from the last
+    # component of the path, so they should be ignored when guessing
+    # the execute permissions from the file extension.
+
+    SUFFIXES = ['', ' ', '   ', '.', '..', ' . .']
+
+    def check(self, ext, mask):
+        filename = os_helper.TESTFN + ext
+        create_file(filename)
+        try:
+            for suffix in self.SUFFIXES:
+                with self.subTest(suffix=suffix):
+                    mode = os.stat(filename + suffix).st_mode
+                    self.assertEqual(mode & 0o111, mask)
+        finally:
+            os_helper.unlink(filename)
+
+    def test_executable_extension(self):
+        for ext in '.exe', '.bat', '.cmd', '.com', '.EXE', '.Bat':
+            with self.subTest(ext=ext):
+                self.check(ext, 0o111)
+
+    def test_not_executable_extension(self):
+        for ext in '.txt', '.py', '.exe.txt', '':
+            with self.subTest(ext=ext):
+                self.check(ext, 0)
+
+    def test_extended_path(self):
+        # The \\?\ prefix disables normalization: trailing spaces and dots
+        # are part of the file name.
+        filename = os.path.abspath(os_helper.TESTFN + '.exe')
+        create_file(filename)
+        self.addCleanup(os_helper.unlink, filename)
+        self.assertEqual(os.stat('\\\\?\\' + filename).st_mode & 0o111, 0o111)
+        self.assertRaises(OSError, os.stat, '\\\\?\\' + filename + ' ')
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2026-08-08-21-40-00.gh-issue-84419.statexe.rst b/Misc/NEWS.d/next/Library/2026-08-08-21-40-00.gh-issue-84419.statexe.rst
new file mode 100644
index 000000000000000..03b90b42e8c3e63
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-08-08-21-40-00.gh-issue-84419.statexe.rst
@@ -0,0 +1,3 @@
+Fix :func:`os.stat` on Windows: trailing dots and spaces, which are ignored
+by the operating system, are no longer taken into account when the execute
+permissions are guessed from the file extension.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index db65d5862440655..cf87aa49e2faf76 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2035,6 +2035,14 @@ win32_wchdir(LPCWSTR path)
 #define HAVE_STRUCT_STAT_ST_FILE_ATTRIBUTES 1
 #define HAVE_STRUCT_STAT_ST_REPARSE_TAG 1
 
+/* The \\?\ prefix disables the path normalization, in particular
+   stripping of trailing dots and spaces. */
+static int
+is_extended_path(const wchar_t *path)
+{
+    return wcsncmp(path, L"\\\\?\\", 4) == 0;
+}
+
 static void
 find_data_to_file_info(WIN32_FIND_DATAW *pFileData,
                        FILE_BASIC_INFO* basic_info,
@@ -2108,12 +2116,20 @@ update_st_mode_from_path(const wchar_t *path, DWORD attr,
            GetSecurityInfo, OpenThreadToken/OpenProcessToken, and
            AccessCheck to check for generic read, write, and execute
            access. */
-        const wchar_t *fileExtension = wcsrchr(path, '.');
-        if (fileExtension) {
-            if (_wcsicmp(fileExtension, L".exe") == 0 ||
-                _wcsicmp(fileExtension, L".bat") == 0 ||
-                _wcsicmp(fileExtension, L".cmd") == 0 ||
-                _wcsicmp(fileExtension, L".com") == 0) {
+        size_t len = wcslen(path);
+        if (!is_extended_path(path)) {
+            /* Trailing dots and spaces are stripped from the last component
+               of the path. */
+            while (len > 0 && (path[len - 1] == L'.' || path[len - 1] == L' ')) {
+                len--;
+            }
+        }
+        if (len >= 4) {
+            const wchar_t *fileExtension = path + len - 4;
+            if (_wcsnicmp(fileExtension, L".exe", 4) == 0 ||
+                _wcsnicmp(fileExtension, L".bat", 4) == 0 ||
+                _wcsnicmp(fileExtension, L".cmd", 4) == 0 ||
+                _wcsnicmp(fileExtension, L".com", 4) == 0) {
                 result->st_mode |= 0111;
             }
         }
@@ -16711,12 +16727,6 @@ static PyType_Spec DirEntryType_spec = {
 
 #ifdef MS_WINDOWS
 
-static int
-is_extended_path(const wchar_t *path)
-{
-    return wcsncmp(path, L"\\\\?\\", 4) == 0;
-}
-
 static wchar_t *
 join_path_filenameW(const wchar_t *path_wide, const wchar_t *filename,
                     int normalize)