Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

In Eclipse Theia versions 0.7.0 and up until including 1.73.1, the `PreferenceUtils.merge` function in `@theia/core` recursively merges preference values without rejecting prototype-related keys (`__proto__`, `constructor`, `prototype`). Because this function is invoked by `PreferenceServiceImpl.doResolve` for every preference resolution across scopes (default, user, workspace, folder), a crafted preference value in a workspace settings file (`.theia/settings.json` or `.vscode/settings.json`) can pollute `Object.prototype` when the user opens the workspace, potentially altering application logic across the Theia process.Show less

axios before 0.33.0 (and 1.x before 1.18.0) can consume inherited properties from nested request option objects when the JavaScript process's Object.prototype has already been polluted by another component. While the top-level merged config uses a null prototype, nested plain objects such as auth and paramsSerializer are cloned into ordinary objects and read without own-property checks. When an application passes placeholder nested objects such as auth: {} or paramsSerializer: {}, inherited username/password values can cause silent injection of an Authorization: Basic header, and inherited encode/serialize values can alter query-string serialization (full serializer replacement requires a function-valued pollution primitive). This is exploitable only in the presence of pre-existing prototype pollution.Show less

axios is vulnerable to read-side prototype-pollution gadgets that can alter request construction when Object.prototype has already been polluted by a separate vulnerability or dependency. In the bodyless method aliases (axios.get(), axios.delete(), axios.head(), axios.options()), inherited data is read via (config || {}).data before config normalization, causing an attacker-controlled body to be sent on requests that did not set one. Additional low-level paths, only reachable when calling exported adapters/helpers (e.g. lib/adapters/http.js, unsafe/helpers/resolveConfig.js) directly with plain configs and no own proxy or paramsSerializer, can inherit polluted proxy values (routing requests through an attacker-controlled proxy) or paramsSerializer values (attacker-controlled URL serialization). These low-level gadgets do not reproduce through normal high-level axios calls on 1.15.2+. The issue is fixed in axios 1.18.0 and 0.33.0.Show less

axios versions >=1.15.2 and <1.18.0 contain prototype-pollution read-side gadgets in Basic auth subfield handling (lib/adapters/http.js and lib/helpers/resolveConfig.js). When an application is already affected by a separate prototype-pollution primitive and makes an axios request with an own auth object that omits the username and/or password properties, axios reads the inherited Object.prototype.username and Object.prototype.password values and uses them to construct an outbound 'Authorization: Basic ...' header. axios itself does not pollute prototypes. The practical impact is outbound request tampering: an attacker who controls the polluted prototype values can inject attacker-chosen Basic auth credentials or replace an existing Authorization header. Credential disclosure is only possible under additional application-specific conditions.Show less

@phun-ky/defaults-deep is a library like lodash defaultsDeep with array preservation and no lodash dependency. Prior to 2.0.5, defaultsDeep() recursively merges user-supplied objects without filtering proto, constructor, and prototype, allowing properties to be written to Object.prototype. This issue is fixed in version 2.0.5.Show less

Pivotick used plain JavaScript objects as lookup tables indexed by caller-controlled graph node identifiers in its tree-layout and cycle-detection components. Node identifiers matching properties inherited from Object.prototype, such as constructor, toString, or __proto__, were not handled as ordinary identifiers. These values could be interpreted as existing inherited properties, resolve to values of an unexpected type, or—in the case of __proto__ assignments—modify the prototype of an internal lookup object. An attacker who can supply graph data containing crafted node identifiers could consequently cause nodes or edges to be silently omitted, produce incorrect hierarchy levels, bypass or corrupt cycle-detection results, or trigger an exception that interrupts graph processing and rendering. This affects the integrity of graph visualisations and analytics and may cause a client-side denial-of-service condition. The affected code also failed to safely handle edges whose source node was absent from the supplied node set. Furthermore, calculating the maximum tree depth by spreading all level values into Math.max() could exceed the JavaScript function-argument limit when processing a sufficiently large graph, resulting in an exception and denial of service. The patch replaces identifier-keyed plain objects with Map instances, ignores invalid edges during tree construction, and calculates the maximum depth iteratively.Show less

DOMPurify before 3.3.2 contains a prototype pollution vulnerability in USE_PROFILES mode that allows attackers to bypass attribute filtering by polluting Array.prototype properties. Attackers can set Array.prototype properties like onclick to true, causing DOMPurify to accept event handlers as allowlisted attributes and resulting in DOM-based XSS when sanitized markup is rendered.Show less

@nevware21/ts-utils is a comprehensive TypeScript/JavaScript utility library. Prior to version 0.14.0, the _copyProps function in lib/src/object/copy.ts uses for...in to iterate over source object properties without an Object.hasOwnProperty check, and does not filter dangerous keys (__proto__, constructor, prototype). This allows an attacker to pollute the prototype chain of all objects in the application. Version 0.14.0 patches the issue.Show less

Versions of the package mongo-object before 3.0.3 are vulnerable to Prototype Pollution via the expandKey() function in util.js. An attacker can modify the JavaScript prototype chain by supplying a crafted property path containing special keys such as __proto__.Show less

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. A Prototype Pollution condition in the `getQueryParam` function `/public/js/main.js` and was addressed in version 1.8.139 by blocking URL query keys matching the pattern `__proto__`. However, this mitigation is incomplete: it only filters top-level `__proto__` keys and fails to sanitize nested forms such as `b[__proto__][polluted]=PWNED`. As a result, an attacker-controlled URL query string can still write into `Object.prototype` on any page that loads `main.js`. Version 1.8.223 contains a updated fix.Show less

A vulnerability has been found in CartoDB carto-api-client 0.5.29. This impacts the function addFilter of the file src/filters.ts. Such manipulation of the argument column leads to improperly controlled modification of object prototype attributes. The attack can be executed remotely. The project was informed of the problem early through an issue report but has not responded yet.Show less

A vulnerability was found in RobinHerbots Inputmask up to 5.0.9. Affected by this issue is the function extendDefaults/extendDefinitions/extendAliases in the library lib/dependencyLibs/extend.js of the component Internal Deep Merge Helper. The manipulation results in improperly controlled modification of object prototype attributes. The attack may be performed from remote. The project was informed of the problem early through an issue report but has not responded yet.Show less

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In 5.0.44 and earlier, the _.merge(target, source) utility exported by @feathersjs/commons recursively merges source into target by iterating Object.keys(source). When source was produced by JSON.parse and contains a __proto__, constructor, or prototype key, that key is returned as an own-enumerable property; the recursive merge then resolves target['__proto__'] to Object.prototype and writes attacker-supplied properties onto it, polluting the prototype for all plain objects in the process for the lifetime of the Node process. This issue is fixed in version 5.0.45.Show less

Hey API is an ecosystem for turning API specifications into production-ready code. Prior to 0.97.3, dist/clients/core/params.ts ships a runtime template copied into generated SDKs as params.gen.ts, and buildClientParams writes unknown slot-prefixed keys such as $body_, $headers_, $path_, and $query_ directly to the corresponding slot, allowing $query___proto__ alongside a legitimate q field to set params.query through params["query"]["__proto__"] = value, call Object.setPrototypeOf(params.query, value), and expose inherited attacker-controlled keys during for..in iteration. This issue is fixed in version 0.97.3.Show less

A security vulnerability has been detected in sagold json-schema-library 11.5.0/11.5.1. This impacts the function parsePropertyDependencies of the file src/keywords/propertyDependencies.ts. The manipulation leads to improperly controlled modification of object prototype attributes. The attack can be initiated remotely. Upgrading to version 11.6.0 will fix this issue. The identifier of the patch is 432287ee6f68a02ce6f015354618486ec427a32d. It is advisable to upgrade the affected component.Show less

Gestor de Oferta is a web application for managing mobility service offerings. Prior to 20260509.0340.15, @tmlmobilidade/utils has a prototype pollution vulnerability in setValueAtPath() in packages/utils/src/generic/value-at-path.ts because unsafe path segments are not blocked. This issue is fixed in version 20260509.0340.15.Show less

AdonisJS is a TypeScript-first web framework. From 10.1.3 until 10.1.5 and 11.0.3, AdonisJS @adonisjs/bodyparser incompletely fixed CVE-2026-25754 because nested multipart field payloads such as user.__proto__.polluted and constructor.prototype still caused lodash _.set() via @poppinss/utils to create plain intermediate objects and pollute Object.prototype. This issue is fixed in versions 10.1.5 and 11.0.3.Show less

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(root, { IN_PLACE: true }) could preserve event-handler attributes on an attacker-controlled <form> root when a descendant name clobbered properties checked by _isClobbered, because _forceRemove no-opped on the parent-less root and _sanitizeAttributes returned early. This issue is fixed in version 3.4.6.Show less

A security vulnerability has been detected in tamagui up to 2.3.0. This affects the function updateConfig of the file code/core/web/src/config.ts. Such manipulation leads to improperly controlled modification of object prototype attributes. The attack may be performed from remote. Upgrading to version 2.3.1 is able to mitigate this issue. The name of the patch is e46af9879b7627934ea4d6d6e46e65cea53abb3d. The affected component should be upgraded.Show less