diff --git a/Misc/NEWS.d/next/Library/2023-07-03-03-46-20.gh-issue-106350.LLcTEe.rst b/Misc/NEWS.d/next/Library/2023-07-03-03-46-20.gh-issue-106350.LLcTEe.rst
new file mode 100644
index 00000000000..681d63a6668
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-07-03-03-46-20.gh-issue-106350.LLcTEe.rst
@@ -0,0 +1,2 @@
+Detect possible memory allocation failure in the libtommath function :c:func:`mp_init`
+used by the ``_tkinter`` module.
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 2aab68ee178..e5377073ff7 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -906,8 +906,9 @@ asBignumObj(PyObject *value)
         return NULL;
     }
     hexchars += neg + 2; /* skip sign and "0x" */
-    mp_init(&bigValue);
-    if (mp_read_radix(&bigValue, hexchars, 16) != MP_OKAY) {
+    if (mp_init(&bigValue) != MP_OKAY ||
+        mp_read_radix(&bigValue, hexchars, 16) != MP_OKAY)
+    {
         mp_clear(&bigValue);
         Py_DECREF(hexstr);
         PyErr_NoMemory();