CVE-2021-41207: TensorFlow-CPU - Division by 0 in ParallelConcat

tensorflow-cpu Updated 02 Oct 2025

Summary

05/11/2021
Yes i
Unrated
Not published

CVE-2021-41207: TensorFlow is an open source platform for machine learning. Affects tensorflow-cpu across 5 version ranges.

< 2.4.4 >= 2.5.0, < 2.5.2 >= 2.6.0, < 2.6.1 >= 2.7.0rc0, < 2.7.0 < f2c3931113eaafe9ef558faaddd48e00a6606235

Fixed in 4 releases; the minimum fixed version depends on the release line you run. How to fix ↓

Also tracked for

The same CVE-2021-41207 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.

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Background

TensorFlow is an open source platform for machine learning. It provides a comprehensive ecosystem of tools, libraries, and resources for developing and deploying machine learning models. TensorFlow-CPU is a specific package that focuses on running TensorFlow on CPUs. It is widely used in various industries and research domains for machine learning tasks. However, a vulnerability has been identified in TensorFlow-CPU that can lead to a division by 0 error in the implementation of the ParallelConcat function.

Vulnerability Detail

The vulnerability in TensorFlow-CPU arises from a lack of input validation in the ParallelConcat function. This can result in a division by 0 error when certain inputs are provided. An attacker could potentially exploit this vulnerability to cause a denial of service or execute arbitrary code. The impact of this vulnerability depends on the context in which TensorFlow-CPU is used and the specific inputs provided. It is important to note that this vulnerability affects multiple versions of TensorFlow-CPU, including versions 2.4.4, 2.5.2, 2.6.1, and 2.7.0rc0.

How To Fix

Latest published version: 2.21.0 as of 22 Oct 2026

pip install --upgrade "tensorflow-cpu==2.21.0"

Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.

If you can't move to the latest

The minimum fixed version depends on the release line you run.

  • < 2.4.4 2.4.4
    pip install --upgrade "tensorflow-cpu==2.4.4"
  • >= 2.5.0, < 2.5.2 2.5.2
    pip install --upgrade "tensorflow-cpu==2.5.2"
  • >= 2.6.0, < 2.6.1 2.6.1
    pip install --upgrade "tensorflow-cpu==2.6.1"
  • >= 2.7.0rc0, < 2.7.0 2.7.0
    pip install --upgrade "tensorflow-cpu==2.7.0"

Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →

Workaround

As a workaround, users can validate the inputs to the ParallelConcat function before invoking it. This can be done by checking the values of the inputs and ensuring that they are within the expected range. Here is an example of how the inputs can be validated in Python:

def safe_parallel_concat(inputs):
    for input in inputs:
        if input == 0:
            raise ValueError('Invalid input: division by 0')
    # Perform the parallel concatenation
    ...

Conclusion

In conclusion, TensorFlow-CPU is vulnerable to a division by 0 error in the ParallelConcat function. This vulnerability can be mitigated by updating to the latest version of TensorFlow-CPU or applying the provided patches. It is important to promptly address this vulnerability to ensure the security and stability of machine learning systems that rely on TensorFlow-CPU. For further support on vulnerability remediation, please contact DevNack.com.

See every vulnerability recorded for tensorflow-cpu →

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FAQ

TensorFlow is an open source platform for machine learning that provides a comprehensive ecosystem of tools and resources for developing and deploying machine learning models.

TensorFlow-CPU is a specific package that focuses on running TensorFlow on CPUs. It is widely used in various industries and research domains for machine learning tasks.

The impact of this vulnerability depends on the context in which TensorFlow-CPU is used and the specific inputs provided. It can potentially lead to a denial of service or arbitrary code execution.

This vulnerability affects TensorFlow-CPU versions 2.4.4, 2.5.2, 2.6.1, and 2.7.0rc0.

To fix this vulnerability, it is recommended to update TensorFlow-CPU to version 2.7.0 or apply the relevant patches for versions 2.6.1, 2.5.2, and 2.4.4.

Related vulnerabilities

Recent vulnerabilities recorded for tensorflow-cpu.

How To Fix

Latest published version: 2.21.0 as of 22 Oct 2026

pip install --upgrade "tensorflow-cpu==2.21.0"

Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.

If you can't move to the latest

The minimum fixed version depends on the release line you run.

  • < 2.4.4 2.4.4
    pip install --upgrade "tensorflow-cpu==2.4.4"
  • >= 2.5.0, < 2.5.2 2.5.2
    pip install --upgrade "tensorflow-cpu==2.5.2"
  • >= 2.6.0, < 2.6.1 2.6.1
    pip install --upgrade "tensorflow-cpu==2.6.1"
  • >= 2.7.0rc0, < 2.7.0 2.7.0
    pip install --upgrade "tensorflow-cpu==2.7.0"

Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →

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