diff --git a/ompi/mpi/tool/cvar_handle_alloc.c b/ompi/mpi/tool/cvar_handle_alloc.c
index 77514825a05..82ebe890032 100644
--- a/ompi/mpi/tool/cvar_handle_alloc.c
+++ b/ompi/mpi/tool/cvar_handle_alloc.c
@@ -9,6 +9,8 @@
  *                         reserved.
  * Copyright (c) 2021      Amazon.com, Inc. or its affiliates.  All Rights
  *                         reserved.
+ * Copyright (c) 2025      Triad National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -41,6 +43,12 @@ int MPI_T_cvar_handle_alloc (int cvar_index, void *obj_handle,
         return MPI_T_ERR_INVALID;
     }
 
+    if (NULL != obj_handle) {
+        if (ompit_obj_invalid(obj_handle)) {
+            return MPI_T_ERR_INVALID_HANDLE;
+        }
+    }
+
     ompi_mpit_lock ();
 
     *handle = NULL;
diff --git a/ompi/mpi/tool/cvar_read.c b/ompi/mpi/tool/cvar_read.c
index b46db2c99c4..90b39d47a22 100644
--- a/ompi/mpi/tool/cvar_read.c
+++ b/ompi/mpi/tool/cvar_read.c
@@ -37,8 +37,10 @@ int MPI_T_cvar_read (MPI_T_cvar_handle handle, void *buf)
         return MPI_T_ERR_NOT_INITIALIZED;
     }
 
-    if (MPI_PARAM_CHECK && NULL == buf) {
-        return MPI_T_ERR_INVALID;
+    if (MPI_PARAM_CHECK) {
+        if ((NULL == buf) || (NULL == handle)) {
+            return MPI_T_ERR_INVALID;
+        }
     }
 
     ompi_mpit_lock ();
diff --git a/ompi/mpi/tool/mpit-internal.h b/ompi/mpi/tool/mpit-internal.h
index 4ee3d9e92a3..f8a6dda65d6 100644
--- a/ompi/mpi/tool/mpit-internal.h
+++ b/ompi/mpi/tool/mpit-internal.h
@@ -5,6 +5,8 @@
  * Copyright (c) 2011      UT-Battelle, LLC. All rights reserved.
  * Copyright (c) 2017      IBM Corporation. All rights reserved.
  * Copyright (c) 2018      Cisco Systems, Inc.  All rights reserved
+ * Copyright (c) 2025      Triad National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -22,8 +24,12 @@
 #include "ompi/include/ompi_config.h"
 #include "ompi/runtime/params.h"
 #include "ompi/communicator/communicator.h"
+#include "ompi/win/win.h"
 #include "ompi/constants.h"
 #include "ompi/datatype/ompi_datatype.h"
+#include "ompi/file/file.h"
+#include "ompi/op/op.h"
+#include "ompi/message/message.h"
 
 #include "mpi.h"
 
@@ -42,6 +48,7 @@ extern volatile uint32_t ompi_mpit_init_count;
 
 int ompit_var_type_to_datatype (mca_base_var_type_t type, MPI_Datatype *datatype);
 int ompit_opal_to_mpit_error (int rc);
+bool ompit_obj_invalid(void *obj_handle);
 
 static inline int mpit_is_initialized (void)
 {
diff --git a/ompi/mpi/tool/mpit_common.c b/ompi/mpi/tool/mpit_common.c
index e47da814f7a..fc84440d14b 100644
--- a/ompi/mpi/tool/mpit_common.c
+++ b/ompi/mpi/tool/mpit_common.c
@@ -8,6 +8,8 @@
  * Copyright (c) 2020      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
+ * Copyright (c) 2025      Triad National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -87,3 +89,118 @@ int ompit_opal_to_mpit_error (int rc)
         return MPI_T_ERR_INVALID;
     }
 }
+
+/*
+ * Check whether a MPI object is valid or not.
+ * If invalid return true, otherwise false.
+ */
+bool ompit_obj_invalid(void *obj_handle)
+{
+    bool ret = true; /* by default return obj is invalid */
+    opal_object_t *opal_obj = NULL;
+    opal_class_t *opal_class;
+    const char *obj_name = NULL;
+
+    if (NULL == obj_handle) {
+        goto fn_exit;
+    }
+
+    /* we are actually evaulating a pointer to an OMPI MPI opaque handle */
+    opal_obj = *(opal_object_t **)obj_handle;
+
+    /*
+     * this should have already been checked by the caller but we do it here too
+     */
+    if (NULL == opal_obj) {
+        goto fn_exit;
+    }
+
+    opal_class = opal_obj->obj_class;
+    if (NULL == opal_class) {
+        goto fn_exit;
+    }
+
+    obj_name = opal_class->cls_name;
+    if (NULL == obj_name) {
+        goto fn_exit;
+    }
+
+    /*
+     * An MPIT C or P var or event can in principle be bound to any of these MPI object types
+     * This code is meant to address, at least in part, the text in section 15.3.2 in the MPI 4.1
+     * standard concerning binding one of the T things to an MPI object.
+     */
+    if (0 == strncmp(obj_name, "ompi_communicator_t", strlen("ompi_communicator_t"))) {
+        ompi_communicator_t *comm = (ompi_communicator_t *)obj_handle;
+        ret = ompi_comm_invalid(comm);
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_win_t", strlen("ompi_win_t"))) {
+        ompi_win_t *win = (ompi_win_t *)obj_handle;
+        ret = ompi_win_invalid(win);
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_file_t", strlen("ompi_file_t"))) {
+        ompi_file_t *file = (ompi_file_t *)obj_handle;
+        ret = ompi_file_invalid(file);
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_instance_t", strlen("ompi_instance_t"))) {
+        ompi_instance_t *instance = (ompi_instance_t *)obj_handle;
+        ret = ompi_instance_invalid(instance);
+        goto fn_exit;
+    }
+
+    /*
+     * following object types don't seem to have robust validity checks so just
+     * do a smoke test for use of NULL objects.
+     */
+    if (0 == strncmp(obj_name, "ompi_info_t", strlen("ompi_info_t"))) {
+        ompi_info_t *info = (ompi_info_t *)obj_handle;
+        ret = (MPI_INFO_NULL == info) ? true : false;
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_datatype_t", strlen("ompi_datatype_t"))) {
+        ompi_datatype_t *datatype = (ompi_datatype_t *)obj_handle;
+        ret = (MPI_DATATYPE_NULL == datatype) ? true : false;
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_request_t", strlen("ompi_request_t"))) {
+        ompi_request_t *request = (ompi_request_t *)obj_handle;
+        ret = (MPI_REQUEST_NULL == request) ? true : false;
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_errhandler_t", strlen("ompi_errhandler_t"))) {
+        ompi_errhandler_t *errhandler = (ompi_errhandler_t *)obj_handle;
+        ret = (MPI_ERRHANDLER_NULL == errhandler) ? true : false;
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_opt_t", strlen("ompi_op_t"))) {
+        ompi_op_t *op = (ompi_op_t *)obj_handle;
+        ret = (MPI_OP_NULL == op) ? true : false;
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_message_t", strlen("ompi_message_t"))) {
+        ompi_message_t *message = (ompi_message_t *)obj_handle;
+        ret = (MPI_MESSAGE_NULL == message) ? true : false;
+        goto fn_exit;
+    }
+
+    if (0 == strncmp(obj_name, "ompi_group_t", strlen("ompi_group_t"))) {
+        ompi_group_t *group = (ompi_group_t *)obj_handle;
+        ret = (MPI_GROUP_NULL == group) ? true : false;
+        goto fn_exit;
+    }
+
+fn_exit:
+    return ret;
+}
+
diff --git a/ompi/mpi/tool/pvar_handle_alloc.c b/ompi/mpi/tool/pvar_handle_alloc.c
index 0400025a11c..b37e05a57e2 100644
--- a/ompi/mpi/tool/pvar_handle_alloc.c
+++ b/ompi/mpi/tool/pvar_handle_alloc.c
@@ -9,6 +9,8 @@
  *                         reserved.
  * Copyright (c) 2021      Amazon.com, Inc. or its affiliates.  All Rights
  *                         reserved.
+ * Copyright (c) 2025      Triad National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -37,6 +39,12 @@ int MPI_T_pvar_handle_alloc(MPI_T_pvar_session session, int pvar_index,
         return MPI_T_ERR_NOT_INITIALIZED;
     }
 
+    if (NULL != obj_handle) {
+        if (ompit_obj_invalid(obj_handle)) {
+            return MPI_T_ERR_INVALID_HANDLE;
+        }
+    }
+
     ompi_mpit_lock ();
 
     do {