In Tensorflow before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, the "SparseFillEmptyRowsGrad" implementation has incomplete validation of the shapes of its arguments. Although "reverse_index_map_t" and "grad_values_t" are accessed in a similar pattern, only "reverse_index_map_t" is validated to be of proper shape. Hence, malicious users can pass a bad "grad_values_t" to trigger an assertion failure in "vec", causing denial of service in serving installations. The issue is patched in commit 390611e0d45c5793c7066110af37c8514e6a6c54, and is released in TensorFlow versions 1.15.4, 2.0.3, 2.1.2, 2.2.1, or 2.3.1."