Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. In versions prior to 5.3.2 or 4.10.19, keywords that are specified in the Parse Server option `requestKeywordDenylist` can be injected via Cloud Code Webhooks or Triggers. This will result in the keyword being saved to the database, bypassing the `requestKeywordDenylist` option. This issue is fixed in versions 4.10.19, and 5.3.2. If upgrade is not possible, the following Workarounds may be applied: Configure your firewall to only allow trusted servers to make request to the Parse Server Cloud Code Webhooks API, or block the API completely if you are not using the feature.

LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. Prior to 0.5.18, the LangSmith JavaScript/TypeScript SDK (langsmith) contains an incomplete prototype pollution fix in its internally vendored lodash set() utility. The baseAssignValue() function only guards against the __proto__ key, but fails to prevent traversal via constructor.prototype. This allows an attacker who controls keys in data processed by the createAnonymizer() API to pollute Object.prototype, affecting all objects in the Node.js process. This vulnerability is fixed in 0.5.18.

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Versions prior to 4.10.18, and prior to 5.3.1 on the 5.X branch, are vulnerable to Remote Code Execution via prototype pollution. An attacker can use this prototype pollution sink to trigger a remote code execution through the MongoDB BSON parser. This issue is patched in version 5.3.1 and in 4.10.18. There are no known workarounds.

Winter is a free, open-source content management system based on the Laravel PHP framework. The Snowboard framework in versions 1.1.8, 1.1.9, and 1.2.0 is vulnerable to prototype pollution in the main Snowboard class as well as its plugin loader. The 1.0 branch of Winter is not affected, as it does not contain the Snowboard framework. This issue has been patched in v1.1.10 and v1.2.1. As a workaround, one may avoid this issue by following some common security practices for JavaScript, including implementing a content security policy and auditing scripts.

Prototype pollution vulnerability in stealjs steal 2.2.4 via the alias variable in babel.js.

Prototype pollution vulnerability in karma-runner grunt-karma 4.0.1 via the key variable in grunt-karma.js.

Prototype pollution vulnerability in function convertLater in npm-convert.js in stealjs steal 2.2.4 via the requestedVersion variable in npm-convert.js.

A prototype pollution vulnerability exists in the function copy in dom.js in the xmldom (published as @xmldom/xmldom) package before 0.8.3 for Node.js via the p variable. NOTE: the vendor states "we are in the process of marking this report as invalid"; however, some third parties takes the position that "A prototype injection/Prototype pollution is not just when global objects are polluted with recursive merge or deep cloning but also when a target object is polluted."

Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. Prior to version 3.0.25, the `unserialize()` function in `locutus/php/var/unserialize` assigns deserialized keys to plain objects via bracket notation without filtering the `__proto__` key. When a PHP serialized payload contains `__proto__` as an array or object key, JavaScript's `__proto__` setter is invoked, replacing the deserialized object's prototype with attacker-controlled content. This enables property injection, for...in propagation of injected properties, and denial of service via built-in method override. This is distinct from the previously reported prototype pollution in `parse_str` (GHSA-f98m-q3hr-p5wq, GHSA-rxrv-835q-v5mh) — `unserialize` is a different function with no mitigation applied. Version 3.0.25 patches the issue.

Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. Starting in version 2.0.39 and prior to version 3.0.25, a prototype pollution vulnerability exists in the `parse_str` function of the npm package locutus. An attacker can pollute `Object.prototype` by overriding `RegExp.prototype.test` and then passing a crafted query string to `parse_str`, bypassing the prototype pollution guard. This vulnerability stems from an incomplete fix for CVE-2026-25521. The CVE-2026-25521 patch replaced the `String.prototype.includes()`-based guard with a `RegExp.prototype.test()`-based guard. However, `RegExp.prototype.test` is itself a writable prototype method that can be overridden, making the new guard bypassable in the same way as the original — trading one hijackable built-in for another. Version 3.0.25 contains an updated fix.

Prototype pollution vulnerability in function extend in babel.js in stealjs steal 2.2.4 via the key variable in babel.js.

Prototype pollution vulnerability in function DEFNODE in ast.js in mishoo UglifyJS 3.13.2 via the name variable in ast.js. NOTE: the vendor considers this an invalid report.

Prototype pollution vulnerability in function resolveShims in resolve-shims.js in thlorenz browserify-shim 3.8.15 via the fullPath variable in resolve-shims.js.

A vulnerability, which was classified as critical, was found in hughsk flat up to 5.0.0. This affects the function unflatten of the file index.js. The manipulation leads to improperly controlled modification of object prototype attributes ('prototype pollution'). It is possible to initiate the attack remotely. Upgrading to version 5.0.1 is able to address this issue. The name of the patch is 20ef0ef55dfa028caddaedbcb33efbdb04d18e13. It is recommended to upgrade the affected component. The identifier VDB-216777 was assigned to this vulnerability.

Prototype pollution vulnerability in 'dotty' versions 0.0.1 through 0.1.0 allows attackers to cause a denial of service and may lead to remote code execution.

Prototype pollution vulnerability in function parseQuery in parseQuery.js in webpack loader-utils via the name variable in parseQuery.js. This affects all versions prior to 1.4.1 and 2.0.3.

A vulnerability was determined in brikcss merge up to 1.3.0. This affects an unknown part. Executing a manipulation of the argument __proto__/constructor.prototype/prototype can lead to improperly controlled modification of object prototype attributes. The attack may be performed from remote. The vendor was contacted early about this disclosure but did not respond in any way.

A vulnerability was determined in 1024bit extend-deep up to 0.1.6. The impacted element is an unknown function of the file index.js. This manipulation of the argument __proto__ causes improperly controlled modification of object prototype attributes. Remote exploitation of the attack is possible. The exploit has been publicly disclosed and may be utilized. The code repository of the project has not been active for many years.

Prototype pollution vulnerability in 'putil-merge' versions1.0.0 through 3.6.6 allows attacker to cause a denial of service and may lead to remote code execution.

flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key "__proto__" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2.

Prototype pollution vulnerability in function resolveShims in resolve-shims.js in thlorenz browserify-shim 3.8.15 via the shimPath variable in resolve-shims.js.

A vulnerability classified as critical has been found in Furqan node-whois. Affected is an unknown function of the file index.coffee. The manipulation leads to improperly controlled modification of object prototype attributes ('prototype pollution'). It is possible to launch the attack remotely. The name of the patch is 46ccc2aee8d063c7b6b4dee2c2834113b7286076. It is recommended to apply a patch to fix this issue. The identifier of this vulnerability is VDB-216252.

Prototype pollution vulnerability in tschaub gh-pages 3.1.0 via the partial variable in util.js.

Prototype pollution vulnerability in function resolveShims in resolve-shims.js in thlorenz browserify-shim 3.8.15 via the k variable in resolve-shims.js.

Prototype pollution vulnerability in function enable in mockery.js in mfncooper mockery commit 822f0566fd6d72af8c943ae5ca2aa92e516aa2cf via the key variable in mockery.js.

This affects the package conf-cfg-ini before 1.2.2. If an attacker submits a malicious INI file to an application that parses it with decode, they will pollute the prototype on the application. This can be exploited further depending on the context.

A vulnerability was identified in higuma web-audio-recorder-js 0.1/0.1.1. Impacted is the function extend in the library lib/WebAudioRecorder.js of the component Dynamic Config Handling. Such manipulation leads to improperly controlled modification of object prototype attributes. It is possible to launch the attack remotely. Attacks of this nature are highly complex. The exploitability is considered difficult. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

Prototype pollution vulnerability in 'deephas' versions 1.0.0 through 1.0.5 allows attacker to cause a denial of service and may lead to remote code execution.

Immutable.js provides many Persistent Immutable data structures. Prior to versions 3.8.3, 4.3.7, and 5.1.5, Prototype Pollution is possible in immutable via the mergeDeep(), mergeDeepWith(), merge(), Map.toJS(), and Map.toObject() APIs. This issue has been patched in versions 3.8.3, 4.3.7, and 5.1.5.

Prototype pollution vulnerability in 'object-hierarchy-access' versions 0.2.0 through 0.32.0 allows attacker to cause a denial of service and may lead to remote code execution.

This affects the package properties-reader before 2.2.0.

This affects the package js-ini before 1.3.0. If an attacker submits a malicious INI file to an application that parses it with parse , they will pollute the prototype on the application. This can be exploited further depending on the context.

Dottie provides nested object access and manipulation in JavaScript. Versions 2.0.4 through 2.0.6 contain an incomplete fix for CVE-2023-26132. The prototype pollution guard introduced in commit `7d3aee1` only validates the first segment of a dot-separated path, allowing an attacker to bypass the protection by placing `__proto__` at any position other than the first. Both `dottie.set()` and `dottie.transform()` are affected. Version 2.0.7 contains an updated fix to address the residual vulnerability.

All versions of package datatables.net are vulnerable to Prototype Pollution due to an incomplete fix for https://snyk.io/vuln/SNYK-JS-DATATABLESNET-598806.

Prototype pollution vulnerability in 'field' versions 0.0.1 through 1.0.1 allows attacker to cause a denial of service and may lead to remote code execution.

oRPC is an tool that helps build APIs that are end-to-end type-safe and adhere to OpenAPI standards. Prior to version 1.13.6, a prototype pollution vulnerability exists in the RPC JSON deserializer of the @orpc/client package. The vulnerability allows unauthenticated, remote attackers to inject arbitrary properties into the global Object.prototype. Because this pollution persists for the lifetime of the Node.js process and affects all objects, it can lead to severe security breaches, including authentication bypass, denial of service, and potentially Remote Code Execution. This issue has been patched in version 1.13.6.

set-in provides the set value of nested associative structure given array of keys. A prototype pollution vulnerability exists in the the npm package set-in (>=2.0.1, < 2.0.5). Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using Array.prototype. This has been fixed in version 2.0.5.

Maker.js is a 2D vector line drawing and shape modeling for CNC and laser cutters. In versions up to and including 0.19.1, the `makerjs.extendObject` function copies properties from source objects without proper validation, potentially exposing applications to security risks. The function lacks `hasOwnProperty()` checks and does not filter dangerous keys, allowing inherited properties and potentially malicious properties to be copied to target objects. A patch is available in commit 85e0f12bd868974b891601a141974f929dec36b8, which is expected to be part of version 0.19.2.

seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, due to improper input validation, a malicious object key can lead to prototype pollution during JSON deserialization. This vulnerability affects only JSON deserialization functionality. This issue is fixed in version 1.4.1.

A Prototype pollution vulnerability in Kibana leads to arbitrary code execution via crafted HTTP requests to machine learning and reporting endpoints.

The Tarkov Data Manager is a tool to manage the Tarkov item data. Prior to 02 January 2025, an authentication bypass vulnerability in the login endpoint allows any unauthenticated user to gain full admin access to the Tarkov Data Manager admin panel by exploiting a JavaScript prototype property access vulnerability, combined with loose equality type coercion. A series of fix commits on 02 January 2025 fixed this and other vulnerabilities.

This affects all versions of package ion-parser. If an attacker submits a malicious INI file to an application that parses it with parse , they will pollute the prototype on the application. This can be exploited further depending on the context.

This affects the package multi-ini before 2.1.2. It is possible to pollute an object's prototype by specifying the constructor.proto object as part of an array. This is a bypass of CVE-2020-28448.

Underscore.deep is a collection of Underscore mixins that operate on nested objects. Versions of `underscore.deep` prior to version 0.5.3 are vulnerable to a prototype pollution vulnerability. An attacker can craft a malicious payload and pass it to `deepFromFlat`, which would pollute any future Objects created. Any users that have `deepFromFlat` or `deepPick` (due to its dependency on `deepFromFlat`) in their code should upgrade to version 0.5.3 as soon as possible. Users unable to upgrade may mitigate this issue by modifying `deepFromFlat` to prevent specific keywords which will prevent this from happening.

Feather-Sequalize cleanQuery method uses insecure recursive logic to filter unsupported keys from the query object. This results in a Remote Code Execution (RCE) with privileges of application.

This affects the package multi-ini before 2.1.1. It is possible to pollute an object's prototype by specifying the proto object as part of an array.

The package bodymen from 0.0.0 are vulnerable to Prototype Pollution via the handler function which could be tricked into adding or modifying properties of Object.prototype using a __proto__ payload. **Note:** This vulnerability derives from an incomplete fix to [CVE-2019-10792](https://security.snyk.io/vuln/SNYK-JS-BODYMEN-548897)

All versions of package safe-eval are vulnerable to Prototype Pollution which allows an attacker to add or modify properties of the Object.prototype.Consolidate when using the function safeEval. This is because the function uses vm variable, leading an attacker to modify properties of the Object.prototype.

Simple-Plist v1.3.0 was discovered to contain a prototype pollution vulnerability via .parse().

The package libnested before 1.5.2 are vulnerable to Prototype Pollution via the set function in index.js. **Note:** This vulnerability derives from an incomplete fix for [CVE-2020-28283](https://security.snyk.io/vuln/SNYK-JS-LIBNESTED-1054930)