diff --git a/onnxruntime/core/providers/cpu/tensor/split.cc b/onnxruntime/core/providers/cpu/tensor/split.cc
index 7f50f3cea0e80..92911103280e7 100644
--- a/onnxruntime/core/providers/cpu/tensor/split.cc
+++ b/onnxruntime/core/providers/cpu/tensor/split.cc
@@ -79,6 +79,8 @@ Status SplitImpl::Compute(OpKernelContext* context) const {
     auto nDims = static_cast<size_t>(split_tensor->Shape()[0]);
     const auto* data = split_tensor->Data<int64_t>();
     split_sizes.assign(data, data + nDims);
+    ORT_RETURN_IF(std::any_of(split_sizes.cbegin(), split_sizes.cend(), [](int64_t v) { return v < 0; }),
+                  "Invalid value in 'split' input. All values must be >= 0.");
   } else {
     split_sizes.assign(split_sizes_.begin(), split_sizes_.end());
   }
diff --git a/onnxruntime/test/providers/cpu/tensor/split_op_test.cc b/onnxruntime/test/providers/cpu/tensor/split_op_test.cc
index 8db1c4d1fef2e..bb0a945612188 100644
--- a/onnxruntime/test/providers/cpu/tensor/split_op_test.cc
+++ b/onnxruntime/test/providers/cpu/tensor/split_op_test.cc
@@ -5,6 +5,7 @@
 #include "core/framework/to_tensor_proto_element_type.h"
 #include "test/providers/provider_test_utils.h"
 #include "test/common/tensor_op_test_utils.h"
+#include "test/util/include/default_providers.h"
 
 namespace onnxruntime {
 namespace test {
@@ -910,5 +911,43 @@ TEST(SplitOperatorTest, Split3Inner) {
   do_test(splits);
 }
 
+TEST(SplitOperatorTest, InvalidValueInSplitInput_NegativeEntry_Axis0) {
+  // Force CPU-only execution: the negative-value guard lives in the CPU Split kernel
+  // Other EPs (CUDA, TensorRT, etc.) have their own Split implementations
+  // that either fail with a different error or hit the framework's negative-shape check
+  // downstream.
+  OpTester test("Split", 13, onnxruntime::kOnnxDomain);
+  test.AddAttribute<int64_t>("axis", 0);
+  test.AddInput<float>("input", {6, 2}, {1.f, 2.f, 3.f, 4.f, 5.f, 6.f, 7.f, 8.f, 9.f, 10.f, 11.f, 12.f});
+  // Sum equals axis dim (8 + -2 == 6) and count matches num outputs, so existing
+  // count/sum guards do not trigger; only the per-value check can catch this case.
+  test.AddInput<int64_t>("split", {2}, {8, -2}, /*is_initializer=*/false);
+  test.AddOutput<float>("output0", {1, 2}, {0.f, 0.f});
+  test.AddOutput<float>("output1", {1, 2}, {0.f, 0.f});
+
+  std::vector<std::unique_ptr<IExecutionProvider>> execution_providers;
+  execution_providers.push_back(DefaultCpuExecutionProvider());
+  test.Run(OpTester::ExpectResult::kExpectFailure,
+           "Invalid value in 'split' input. All values must be >= 0.",
+           {}, nullptr, &execution_providers);
+}
+
+TEST(SplitOperatorTest, InvalidValueInSplitInput_NegativeEntry_NegativeAxis) {
+  // Same reason as above: force CPU-only. Negative entry in the leading position;
+  // sum still matches the split-axis dim (-1 + 5 == 4).
+  OpTester test("Split", 13, onnxruntime::kOnnxDomain);
+  test.AddAttribute<int64_t>("axis", -1);
+  test.AddInput<float>("input", {2, 4}, {1.f, 2.f, 3.f, 4.f, 5.f, 6.f, 7.f, 8.f});
+  test.AddInput<int64_t>("split", {2}, {-1, 5}, /*is_initializer=*/false);
+  test.AddOutput<float>("output0", {2, 1}, {0.f, 0.f});
+  test.AddOutput<float>("output1", {2, 1}, {0.f, 0.f});
+
+  std::vector<std::unique_ptr<IExecutionProvider>> execution_providers;
+  execution_providers.push_back(DefaultCpuExecutionProvider());
+  test.Run(OpTester::ExpectResult::kExpectFailure,
+           "Invalid value in 'split' input. All values must be >= 0.",
+           {}, nullptr, &execution_providers);
+}
+
 }  // namespace test
 }  // namespace onnxruntime