Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.0 through 1.4.16 contain a prototype pollution vulnerability in `mergeDeep` after merging results of two standard schema validations with the same key. Due to the ordering of merging, there must be an any type that is set as a standalone guard, to allow for the `__proto__ prop` to be merged. When combined with GHSA-8vch-m3f4-q8jf this allows for a full RCE by an attacker. This issue is fixed in version 1.4.17. To workaround, remove the `__proto__ key` from body.

In Plotly plotly.js before 2.25.2, plot API calls have a risk of __proto__ being polluted in expandObjectPaths or nestedProperty.

NPM package query-parser-string 1.0.0 is vulnerable to Prototype Pollution. The package does not properly sanitize user supplied query parameters and merges them to the newly created object.

npm package parse-ini v1.0.6 is vulnerable to Prototype Pollution in index.js().

The value function in jsonpath 1.1.1 lib/index.js is vulnerable to Prototype Pollution.

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.

A vulnerability exists in the 'dagre-d3-es' Node.js package version 7.0.9, specifically within the 'bk' module's addConflict function, which fails to properly sanitize user-supplied input during property assignment operations. This flaw allows attackers to exploit prototype pollution vulnerabilities by injecting malicious input values (e.g., "__proto__"), enabling unauthorized modification of the JavaScript Object prototype chain. Successful exploitation could lead to denial of service conditions, unexpected application behavior, or potential execution of arbitrary code in contexts where polluted properties are later accessed or executed. The issue affects versions prior to 7.0.11 and remains unpatched at the time of disclosure.

A Prototype Pollution vulnerability in the util-deps.addFileDepend function of magix-combine-ex versions thru 1.2.10 allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.

"protobuf.js (aka protobufjs) 6.10.0 through 7.x before 7.2.5 allows Prototype Pollution, a different vulnerability than CVE-2022-25878. A user-controlled protobuf message can be used by an attacker to pollute the prototype of Object.prototype by adding and overwriting its data and functions. Exploitation can involve: (1) using the function parse to parse protobuf messages on the fly, (2) loading .proto files by using load/loadSync functions, or (3) providing untrusted input to the functions ReflectionObject.setParsedOption and util.setProperty.

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 5.5.2 and 6.2.1, an attacker can use a prototype pollution sink to trigger a remote code execution through the MongoDB BSON parser. A patch is available in versions 5.5.2 and 6.2.1.

In JetBrains YouTrack before 2026.2.16593 the websandbox bridge was vulnerable to a prototype pollution attack

All versions of package nodee-utils are vulnerable to Prototype Pollution via the deepSet function.

This affects the package express-fileupload before 1.1.8. If the parseNested option is enabled, sending a corrupt HTTP request can lead to denial of service or arbitrary code execution.

The package bmoor before 0.8.12 are vulnerable to Prototype Pollution via the set function.

All versions of package promisehelpers are vulnerable to Prototype Pollution via the insert function.

Versions of package locutus before 2.0.12 are vulnerable to prototype Pollution via the php.strings.parse_str function.

All versions of package confucious are vulnerable to Prototype Pollution via the set function.

Prototype pollution vulnerability in dot-prop npm package versions before 4.2.1 and versions 5.x before 5.1.1 allows an attacker to add arbitrary properties to JavaScript language constructs such as objects.

The package y18n before 3.2.2, 4.0.1 and 5.0.5, is vulnerable to Prototype Pollution.

All versions of package node-oojs are vulnerable to Prototype Pollution via the setPath function.

vm2 is an open source vm/sandbox for Node.js. From 3.9.6 to 3.10.5, vm2's bridge exposes mutable proxies for real host-realm intrinsic prototypes and then forwards sandbox writes into the underlying host objects with otherReflectSet() and otherReflectDefineProperty(), which lets attacker-controlled JavaScript running in a default VM or inherited NodeVM mutate shared host Object.prototype, Array.prototype, and Function.prototype from inside the sandbox This vulnerability is fixed in 3.11.0.

vConsole v3.15.0 was discovered to contain a prototype pollution due to incorrect key and value resolution in setOptions in core.ts.

Prototype Pollution in GitHub repository antfu/utils prior to 0.7.3.

Prototype Pollution in Kibana can lead to code injection via unrestricted file upload combined with path traversal.

All versions of the package flatnest are vulnerable to Prototype Pollution via the nest() function in the flatnest/nest.js file.

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.

billboard.js before 3.15.1 was discovered to contain a prototype pollution via the function generate, which could allow attackers to execute arbitrary code or cause a Denial of Service (DoS) via injecting arbitrary properties.

Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocity templates. If an application renders a template controlled by an attacker, it is possible to modify Object.prototype, potentially leading to Denial of Service (DoS) or Remote Code Execution (RCE) depending on the server environment.

Versions of the package tough-cookie before 4.1.3 are vulnerable to Prototype Pollution due to improper handling of Cookies when using CookieJar in rejectPublicSuffixes=false mode. This issue arises from the manner in which the objects are initialized.

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.

This affects the package properties-reader before 2.2.0.

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.

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 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.

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.

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.

Beaker before 0.8.9 allows a sandbox escape, enabling system access and code execution. This occurs because Electron context isolation is not used, and therefore an attacker can conduct a prototype-pollution attack against the Electron internal messaging API.

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.

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.

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.

Versions of handlebars prior to 4.3.0 are vulnerable to Prototype Pollution leading to Remote Code Execution. Templates may alter an Object's __proto__ and __defineGetter__ properties, which may allow an attacker to execute arbitrary code through crafted payloads.

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.

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.

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.

2o3t-utility v0.1.2 was discovered to contain a prototype pollution via the function extend. This vulnerability allows attackers to execute arbitrary code or cause a Denial of Service (DoS) via injecting arbitrary properties.

chase-moskal snapstate v0.0.9 was discovered to contain a prototype pollution via the function attemptNestedProperty. This vulnerability allows attackers to execute arbitrary code or cause a Denial of Service (DoS) via injecting arbitrary properties.

A Prototype Pollution issue in Cronvel Tree-kit v.0.7.4 and before allows a remote attacker to execute arbitrary code via the extend function.

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 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.