Description
Versions of extend prior to 3.0.2 (for 3.x) and 2.0.2 (for 2.x) are vulnerable to Prototype Pollution. The extend() function allows attackers to modify the prototype of Object causing the addition or modification of an existing property that will exist on all objects.
Recommendation
Update the extend package to the latest compatible version. Followings are version details:
Affected version(s): **>= 1.1.3, < 2.0.2 >= 3.0.0, < 3.0.2** Patched version(s): **2.0.2 3.0.2**
References
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Start a free scanRelated Issues
- mockjs vulnerable to Prototype Pollution via the Util.extend function - CVE-2023-26158
- Prototype Pollution in lodash - CVE-2018-3721
- Prototype Pollution in merge-options - CVE-2018-3752
- Prototype Pollution in async merge-object - CVE-2018-3753
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See something that needs correcting? Let us knowUpdated January 22, 2026