diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-04-21-19-29-29.gh-issue-148850.MSH0J_.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-21-19-29-29.gh-issue-148850.MSH0J_.rst
new file mode 100644
index 00000000000000..324d1610310158
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-21-19-29-29.gh-issue-148850.MSH0J_.rst
@@ -0,0 +1 @@
+Fix the memory sanitizer false positive in :func:`os.getrandom`.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index e5ce487723b25b..c07d0f89d4e6f0 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -17195,6 +17195,10 @@ os_getrandom_impl(PyObject *module, Py_ssize_t size, int flags)
         goto error;
     }
 
+#ifdef _Py_MEMORY_SANITIZER
+    __msan_unpoison(data, size);
+#endif
+
     return PyBytesWriter_FinishWithSize(writer, n);
 
 error: