CVE-2021-37635: Google Tensorflow

High severity, CVSS 7.1. EPSS: 0.2% chance of exploitation in the next 30 days.

TensorFlow is an end-to-end open source platform for machine learning. In affected versions the implementation of sparse reduction operations in TensorFlow can trigger accesses outside of bounds of heap allocated data. The [implementation](https://github.com/tensorflow/tensorflow/blob/a1bc56203f21a5a4995311825ffaba7a670d7747/tensorflow/core/kernels/sparse_reduce_op.cc#L217-L228) fails to validate that each reduction group does not overflow and that each corresponding index does not point to outside the bounds of the input tensor. We have patched the issue in GitHub commit 87158f43f05f2720a374f3e6d22a7aaa3a33f750. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.

Affected products

• Google Tensorflow: from 2.3.0, before 2.3.4 (fixed in 2.3.4); from 2.4.0, before 2.4.3 (fixed in 2.4.3); version 2.5.0 only; version 2.6.0 only

Published 2021-08-12. Last modified 2026-06-17.