Weakness (CWE)
CWE-1321: Improperly Controlled Modification of Object Prototype Attributes
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
How to prevent it (5 mitigations)
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Implementation
By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
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Architecture and Design
By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
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Implementation
When handling untrusted objects, validating using a schema can be used.
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Implementation
By using an object without prototypes (via Object.create(null) ), adding object prototype attributes by accessing the prototype via the special attributes becomes impossible, mitigating this weakness.
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Implementation
Map can be used instead of objects in most cases. If Map methods are used instead of object attributes, it is not possible to access the object prototype or modify it.
Source: MITRE CWE-1321
712 results · Feed
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Medium 4.7
Handlebars.js has Prototype Pollution Leading to XSS through Partial Template Injection
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, `resolvePartial()` in the Handlebars runtime resolves partial names via a plain property lookup on `options.partials` without guarding against prot…
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Medium 5.3
Picomatch: Method Injection in POSIX Character Classes causes incorrect Glob Matching
Picomatch is a glob matcher written JavaScript. Versions prior to 4.0.4, 3.0.2, and 2.3.2 are vulnerable to a method injection vulnerability affecting the `POSIX_REGEX_SOURCE` object. Because the object inherits from `Object.prototype`, specially crafted POSI…
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Critical —
Convict has Prototype Pollution via startsWith() function
### Summary A prototype pollution vulnerability exists in the latest version of the convict npm package (6.2.4). Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input started with a forbidden key, it is still pos…
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Critical —
Convict has prototype pollution via load(), loadFile(), and schema initialization
### Impact Two unguarded prototype pollution paths exist, not covered by previous fixes: 1. `config.load()` / `config.loadFile()` — `overlay()` recursively merges config data without checking for forbidden keys. Input containing` __proto__` or `constructor.pr…
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Critical 9.4
n8n Vulnerable to Prototype Pollution in XML & GSuiteAdmin node parameters lead to RCE
n8n is an open source workflow automation platform. Prior to versions 2.14.1, 2.13.3, and 1.123.27, an authenticated user with permission to create or modify workflows could exploit a prototype pollution vulnerability in the XML and the GSuiteAdmin nodes. By …
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High 8.9
flatted: Prototype Pollution via parse()
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 …
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High 7.5
Qwik has array method pollution in FormData processing, allowing type confusion and DoS
Qwik is a performance-focused JavaScript framework. Versions prior to 1.19.2 improperly inferred arrays from dotted form field names during FormData parsing. By submitting mixed array-index and object-property keys for the same path, an attacker could cause u…
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High 8.2
Parse Server's Cloud function dispatch crashes server via prototype chain traversal
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.24 and 8.6.47, remote clients can crash the Parse Server process by calling a cloud function endpoint with a crafted function name tha…
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Medium 5.3
Parse Server vulnerable to schema poisoning via prototype pollution in deep copy
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.20 and 8.6.44, an attacker can bypass the default request keyword denylist protection and the class-level permission for adding fields…
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Medium 6.5
Elysia Cookie Value Prototype Pollution
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to version 1.4.27, an Elysia cookie can be overridden by prototype pollution , eg. `__proto__`. This issue is patched in 1.4…
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Medium 4.3
OpenClaw < 2026.2.21 - Prototype Pollution via Debug Override Path
OpenClaw versions prior to 2026.2.21 accept prototype-reserved keys in runtime /debug set override object values, allowing prototype pollution attacks. Authorized /debug set callers can inject __proto__, constructor, or prototype keys to manipulate object pro…
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Low 3.5
Lagom WHMCS Template Datatables prototype pollution
A vulnerability was found in Lagom WHMCS Template up to 2.3.7. Impacted is an unknown function of the component Datatables. The manipulation results in improperly controlled modification of object prototype attributes. It is possible to launch the attack remo…
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Critical 9.9CVE-2026-32621 Public exploit
Apollo Federation has prototype pollution via incomplete key sanitization
Apollo Federation is an architecture for declaratively composing APIs into a unified graph. Prior to 2.9.6, 2.10.5, 2.11.6, 2.12.3, and 2.13.2, a vulnerability exists in query plan execution within the gateway that may allow pollution of Object.prototype in c…
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Low —
Sveltejs devalue's `devalue.parse` and `devalue.unflatten` emit objects with `__proto__` own properties
In some circumstances, `devalue.parse` and `devalue.unflatten` could emit objects with `__proto__` own properties. This in and of itself is not a security vulnerability (and is possible with, for example, `JSON.parse` as well), but it can result in prototype …
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Medium 6.3
devalue has prototype pollution in devalue.parse and devalue.unflatten
Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. In devalue v5.6.3 and earlier, devalue.parse and devalue.unflatten were susceptible to prototype pollution via maliciously crafted pay…
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High 8.8
Parse Server has Denial of Service (DoS) and Cloud Function Dispatch Bypass via Prototype Chain Resolution
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.13 and 9.5.1-alpha.2, an unauthenticated attacker can crash the Parse Server process by calling a Cloud Function endpoint with a prototype pro…
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High 8.7
Immutable.js: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in immutable
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 pa…
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Critical 9.3
oRPC: Prototype Pollution in `@orpc/client` via `StandardRPCJsonSerializer` Deserialization
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 unauthe…
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High 8.2
RustDesk Encrypts Local Passwords with World-Readable Machine ID and Fixed Zero Nonce (XSalsa20-Poly1305)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), Use of Password Hash With Insufficient Computational Effort vulnerability in rustdesk-client RustDesk Client rustdesk, hbb_common on Windows, MacOS, Linux (Password sec…
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Medium 6.3
Dottie vulnerable to prototype pollution bypass via non-first path segments in set() and transform()
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 pa…
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Medium 5.0CVE-2026-2964 Public exploit
higuma web-audio-recorder-js Dynamic Config Handling WebAudioRecorder.js extend prototype pollution
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 …
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Critical 9.4CVE-2026-27212 Public exploit
Swiper has a Prototype Pollution Vulnerability
Swiper is a free and mobile touch slider with hardware accelerated transitions and native behavior. Versions 6.5.1 through 12.1.1 have a Prototype pollution vulnerability. The vulnerability resides in line 94 of shared/utils.mjs, where the indexOf() function …
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Low —
devalue `uneval`ed code can create objects with polluted prototypes when `eval`ed
Under certain circumstances, `uneval`ing untrusted data can produce output code that will create objects with polluted prototypes when later `eval`ed, meaning the output data can be a different shape from the input data.
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High 7.5
A State Pollution vulnerability was discovered in the TON Virtual Machine (TVM) before v2025.04. The issue exists in th…
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Critical 9.4
Prototype pollution in set-in
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 w…
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Critical 9.8
CASL Ability, versions 2.4.0 through 6.7.4, contains a prototype pollution vulnerability.
CASL Ability, versions 2.4.0 through 6.7.4, contains a prototype pollution vulnerability.
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Critical 9.1
@nyariv/sandboxjs has host prototype pollution from sandbox via array intermediary (sandbox escape)
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.31, a sandbox escape vulnerability allows sandboxed code to mutate host built-in prototypes by laundering the isGlobal protection flag through array literal intermediaries. When a global prototype ref…
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High 7.5
Axios affected by Denial of Service via __proto__ Key in mergeConfig
Axios is a promise based HTTP client for the browser and Node.js. Prior to versions 0.30.3 and 1.13.5, the mergeConfig function in axios crashes with a TypeError when processing configuration objects containing __proto__ as an own property. An attacker can tr…
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High 7.2
AdonisJS multipart body parsing has Prototype Pollution issue
AdonisJS is a TypeScript-first web framework. Prior to versions 10.1.3 and 11.0.0-next.9, a prototype pollution vulnerability in AdonisJS multipart form-data parsing may allow a remote attacker to manipulate object prototypes at runtime. This issue has been p…
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Critical 9.4
Locutus is vulnerable to Prototype Pollution
Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. In versions from 2.0.12 to before 2.0.39, a prototype pollution vulnerability exists in locutus. Despite a previous fix that attempted to mitigate prototype pollutio…
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Critical 9.3
Prototype Pollution via FormData Processing in Qwik City
Qwik is a performance focused javascript framework. Prior to version 1.19.0, a prototype pollution vulnerability exists in the formToObj() function within @builder.io/qwik-city middleware. The function processes form field names with dot notation (e.g., user.…
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Critical 10.0
SandboxJS Prototype Pollution -> Sandbox Escape -> RCE
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.27, SanboxJS does not properly restrict __lookupGetter__ which can be used to obtain prototypes, which can be used for escaping the sandbox / remote code execution. This vulnerability is fixed in 0.8.…
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Critical 9.4CVE-2026-25047 Public exploit
deepHas vulnerable to Prototype Pollution via constructor.prototype
deepHas provides a test for the existence of a nested object key and optionally returns that key. A prototype pollution vulnerability exists in version 1.0.7 of the deephas npm package that allows an attacker to modify global object behavior. This issue was f…
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Medium 6.5
Maker.js Vulnerable to Unsafe Property Copying in makerjs.extendObject
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 t…
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Medium 4.9
NocoDB Vulnerable to Prototype Pollution in Connection Test Endpoint, Leading to DoS
NocoDB is software for building databases as spreadsheets. Prior to version 0.301.0, an authenticated user with org-level-creator permissions can exploit prototype pollution in the `/api/v2/meta/connection/test` endpoint, causing all database write operations…
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Critical 9.8
JSONPath vulnerable to Prototype Pollution due to insufficient input validation of object keys in lib/index.js
The value function in jsonpath 1.1.1 lib/index.js is vulnerable to Prototype Pollution.
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High 7.3
seroval Affected by Prototype Pollution via JSON Deserialization
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. T…
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Medium 6.9CVE-2025-13465 Public exploit
Prototype Pollution Vulnerability in Lodash _.unset and _.omit functions
The _.unset and _.omit functions in Lodash are vulnerable to prototype pollution. An attacker can pass crafted paths which cause Lodash to delete methods from global prototypes. The issue permits deletion of properties but does not allow overwriting their ori…
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Critical 9.8
Tarkov Data Manager Authentication Bypass vulnerability
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 exploi…
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Medium 5.0
carboneio carbone Formatter input.js prototype pollution
A weakness has been identified in carboneio carbone up to fbcd349077ad0e8748be73eab2a82ea92b6f8a7e. This impacts an unknown function of the file lib/input.js of the component Formatter Handler. Executing a manipulation can lead to improperly controlled modifi…