CVE-2019-10745: Prototype Pollution in assign-deep

assign-deep Updated 02 Oct 2025

Summary

21/08/2019
Yes i
High
7.5

CVE-2019-10745: assign-deep Vulnerable to Prototype Pollution. Affects assign-deep across 2 version ranges.

< 0.4.8 >= 1.0.0, < 1.0.1

Fixed in 0.4.8 or 1.0.1, depending on the release line you run. How to fix ↓

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Background

The assign-deep package is an npm package that provides a function called assign for deep merging objects. It is commonly used in JavaScript applications to merge multiple objects into one. However, versions prior to 1.0.1 and 0.4.8 of assign-deep are vulnerable to Prototype Pollution.

Vulnerability Detail

The vulnerability in assign-deep arises from the assign function's failure to validate the properties it updates in an object. This allows attackers to modify the prototype of an object, leading to the addition or modification of existing properties on all objects. This type of attack is known as Prototype Pollution and can have severe consequences, such as unauthorized access, data tampering, or denial of service.

How To Fix

Latest published version: 1.0.1 as of 23 Oct 2026

npm install assign-deep@1.0.1

The newest release already contains this fix.

If you can't move to the latest

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

  • < 0.4.8 0.4.8
    npm install assign-deep@0.4.8

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

Workaround

There is no known workaround for this vulnerability. It is essential to upgrade to the fixed versions of the assign-deep package.

Conclusion

The assign-deep package prior to versions 1.0.1 and 0.4.8 is vulnerable to Prototype Pollution. It is crucial to upgrade to the fixed versions to mitigate the risk of unauthorized access, data tampering, or denial of service. For further support on vulnerability remediation, contact DevNack.com.

See every vulnerability recorded for assign-deep →

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FAQ

Prototype Pollution is a vulnerability that occurs when an attacker can modify the prototype of an object, leading to the addition or modification of properties on all objects.

Prototype Pollution can have severe consequences, including unauthorized access, data tampering, or denial of service.

Versions prior to 1.0.1 and 0.4.8 of assign-deep are vulnerable to Prototype Pollution.

To fix this vulnerability, upgrade to versions 1.0.1, 0.4.8, or later of the assign-deep package.

No, there is no known workaround for this vulnerability. Upgrading to the fixed versions is the recommended solution.

Related vulnerabilities

Recent vulnerabilities recorded for assign-deep.

How To Fix

Latest published version: 1.0.1 as of 23 Oct 2026

npm install assign-deep@1.0.1

The newest release already contains this fix.

If you can't move to the latest

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

  • < 0.4.8 0.4.8
    npm install assign-deep@0.4.8

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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