CVE-2021-37659

What it is

TensorFlow is an end-to-end open source platform for machine learning. In affected versions an attacker can cause undefined behavior via binding a reference to null pointer in all binary cwise operations that don't require broadcasting (e.g., gradients of binary cwise operations). The [implementation](https://github.com/tensorflow/tensorflow/blob/84d053187cb80d975ef2b9684d4b61981bca0c41/tensorflow/core/kernels/cwise_ops_common.h#L264) assumes that the two inputs have exactly the same number of elements but does not check that. Hence, when the eigen functor executes it triggers heap OOB reads and undefined behavior due to binding to nullptr. We have patched the issue in GitHub commit 93f428fd1768df147171ed674fee1fc5ab8309ec. 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.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-08-12 21:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:00 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 7.3 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-08-12 21:15 UTC

Last modified

2026-06-17 04:00 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-125 · Out-of-bounds read

Record status

Modified

Affected

• Google Tensorflow < 2.3.4
• Google Tensorflow < 2.4.3
• Google Tensorflow 2.5.0
• Google Tensorflow 2.6.0

Attack profile CVSS 3.1 · 7.3

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-37659.md and follow it. Check whether this project is affected by CVE-2021-37659. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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