CVE Database

CVE-2026-92781 Medium · 6.3 CWE-1321 Sep 16, 2026

Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via builder.userAttributes

Builder.io Gen2 SDKs through versions 5.2.11 and 0.25.13 contain a prototype pollution vulnerability in the unflatten helper that processes builder.userAttributes query parameters without prototype guards. Attackers can craft preview links with __proto__ or prototype segments to pollute Object.prototype in a visitor's browser when the SDK processes the malicious URL.

CVE-2026-92779 High · 7.6 CWE-1321 Sep 16, 2026

Builder.io Gen2 SDKs through 5.2.11 Prototype Pollution via Bindings

Builder.io Gen2 SDKs through versions 5.2.11 and 0.25.13 contain a prototype pollution vulnerability in the deep-set helper function that processes content block bindings without validation. Attackers can craft content blocks with binding keys containing __proto__, prototype, or constructor paths to pollute Object.prototype during rendering, affecting all subsequent objects created in the process including other tenants' renders.

CVE-2026-69200 Low · 3.7 CWE-1321 Sep 16, 2026

node-opcua: Prototype Pollution via internal `fieldsToJson()` implementation (Related to CVE-2024-57086)

node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to node-opcua-client 2.145.0, the internal fieldsToJson method in packages/node-opcua-client/source/alarms_and_conditions/client_alarm.ts directly assigns unsanitized field names and allows a __proto__.pollutedKey path to modify Object.prototype. Successful exploitation requires an application to expose attacker-controlled event fields to fieldsToJson and may cause denial of service or application logic corruption. This vulnerability is fixed in 2.145.0.

CVE-2026-55451 High · 8.3 CWE-1321 Sep 14, 2026

gettext-converter: Prototype pollution in js2i18next() via crafted translation keys

gettext-converter provides gettext resource conversion utilities for JavaScript. Prior to 1.3.3, js2i18next() in lib/js2i18next.js splits nested translation keys using options.keyseparator, whose default value consists of two number signs, and uses each segment as a dynamic object key without rejecting __proto__, constructor, or prototype. When an application converts untrusted PO or i18next translation data, a __proto__ segment resolves Object.prototype as the nested write target and Object.assign writes attacker-controlled translated properties onto the process-wide prototype. The resulting prototype pollution can cause denial of service and may enable application-dependent follow-on attacks. This issue is fixed in version 1.3.3.

CVE-2026-61534 Critical · 9.1 CWE-1321 Sep 14, 2026

Yayson: Prototype pollution in the Store/LegacyStore deserialization

Yayson is a library for serializing and reading JSON API data in JavaScript. Prior to 4.3.0, Store and LegacyStore use attacker-controlled JSON:API type, id, and relationship names as keys in plain-object lookup tables in src/yayson/store.ts and src/yayson/legacy-store.ts. A document whose type is __proto__ causes model-cache writes to modify Object.prototype, with the attacker controlling the polluted property name through id and its value through attributes. The malicious type can also be supplied by an included resource, and LegacyStore is reachable when a configured types mapping resolves to __proto__. Unsafe relationship names including __proto__, constructor, and prototype provide additional document-derived member paths. The resulting process-wide prototype pollution can cause denial of service and logic corruption; authorization bypass or code execution depends on suitable gadgets in the consuming application. This issue is fixed in version 4.3.0.

CVE-2026-90771 Low · 3.7 CWE-1321 Sep 13, 2026

joi before 17.13.8 and 18.2.9 Prototype Pollution via messages

joi before versions 17.13.8 and 18.2.9 contains a prototype pollution vulnerability in the messages compilation function that accepts __proto__ as an error code. Attackers can supply __proto__ keys in custom messages to replace the returned object's prototype, breaking downstream code relying on Object.prototype methods.

CVE-2026-89011 High · 7.1 CWE-1321 Sep 10, 2026

isomorphic-git < 1.42.0 Prototype Pollution via getRemoteInfo

isomorphic-git before 1.42.0 contains a prototype pollution vulnerability in the getRemoteInfo function that allows a malicious Git server operator to pollute Object.prototype by advertising crafted ref names containing '__proto__' path segments during ref negotiation. Attackers controlling a Git server can advertise a specially crafted ref such as '__proto__/corsProxy' to reroute all subsequent network operations through an attacker-controlled proxy, causing isomorphic-git to invoke the victim's onAuth callback and transmit credentials to the attacker when the victim calls getRemoteInfo with an attacker-supplied URL.

CVE-2026-86078 Medium · 6.5 CWE-1321 Sep 8, 2026

n8n: Prototype Pollution via Workflow Structure Summary Can Lead to Denial of Service

n8n is an open source workflow automation platform. Prior to 2.37.7 and 2.38.2, the Instance AI workflow summary used node names and connection keys from stored workflows as ordinary object keys. A workflow submitted through the REST API could contain __proto__ or constructor, causing nested writes to reach Object.prototype in the main n8n process and disrupt later requests. The affected function is summarizeWorkflowStructure in packages/@n8n/instance-ai/src/tools/workflows/summarize-workflow.ts. This issue is fixed in versions 2.37.7 and 2.38.2.

CVE-2026-81994 Medium · 6.3 CWE-1321 Sep 8, 2026

Acrobat Reader | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (CWE-1321)

Acrobat Reader is affected by an Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability that could lead to arbitrary file system read. An attacker could exploit this vulnerability to access sensitive files and directories outside the intended access scope. Exploitation of this issue requires user interaction in that a victim must open a malicious file. Scope is changed.

CVE-2026-85625 High · 8.1 CWE-1321 Sep 4, 2026

sift 17.1.3 Prototype Pollution Remote Code Execution via $where

sift (sift.js) 17.1.3 enumerates query keys with for...in, which walks the object prototype chain, and dispatches any matched operator key including $where. The $where operation compiles a string value into a function using new Function unless CSP_ENABLED is set (not set by default). As a result, if a prototype-pollution primitive elsewhere in the process sets Object.prototype.$where to a malicious string, even benign filter calls such as sift({}) execute arbitrary JavaScript. Additionally, passing an untrusted query object containing a string $where directly to sift results in code execution under the default configuration.

CVE-2026-85063 Medium · 6.9 CWE-1321 Sep 3, 2026

node-csv: Prototype replacement still reachable via columns path

node-csv is a full-featured CSV parser with a simple API that is tested against large datasets. Prior to 7.0.2, csv-parse with the columns and group_columns_by_name options enabled treats a duplicate __proto__ header as an existing property in packages/csv-parse/lib/api/index.js, assigns an attacker-controlled array through obj['__proto__'], and replaces the parsed record object's prototype. A malicious CSV header can therefore inject inherited array values into the returned record, hide those inherited values from JSON serialization, and affect property enumeration and type or shape checks in applications that process the record. This issue is fixed in version 7.0.2.

CVE-2026-63376 High · 8.2 CWE-1321 Sep 3, 2026

toml-node: Prototype Pollution Leads to `Object.prototype` Corruption via `__proto__` Key-Path Desynchronization

toml-node is a TOML parser for Node.js and the browser. Prior to 4.1.2, toml.parse() in lib/compiler.js can be tricked by a table path such as a.b.y.__proto__.__proto__, allowing traversal from a scalar value into Number.prototype and Object.prototype. The currentPath tracking value uses both arrays and strings, so valueAssignments records a comma-joined path such as a,b.y while deepRef checks the dot-joined path a.b.y, allowing the duplicate-key guard to miss and attacker-controlled keys to be written to Object.prototype. A table-array prefix-clearing path in addTableArray can also erase guard state before the same __proto__ traversal. Injected properties become visible throughout the Node.js process and can cause denial of service, logic or authorization bypass, or code execution when an application contains a suitable gadget. This issue is fixed in version 4.1.2.

CVE-2026-82404 High · 8.3 CWE-1321 Sep 2, 2026

TOON: Prototype pollution when decoding untrusted TOON input

TOON is a compact, human-readable serialization of JSON data for LLM prompts. Prior to 2.3.1, decoding attacker-controlled TOON with a __proto__, constructor, or prototype key wrote through the object prototype chain instead of creating an own property, polluting Object.prototype for the runtime. In packages/toon/src/decode/expand.ts, the expandPaths: 'safe' path and insertPathSafe function made dotted keys such as a.__proto__.x the strongest vector, while plain nested objects, tabular rows, quoted keys, and streaming decode were also affected. The encoder also dropped own __proto__ properties and could invoke an inherited setter during normalization. Services that decode untrusted TOON could experience denial of service or, when a suitable downstream gadget is present, remote code execution. This issue is fixed in version 2.3.1.

CVE-2026-84368 Low · 3.7 CWE-1321 Sep 1, 2026

joi: Prototype pollution via a `__proto__` language key in custom messages

joi is a schema description language and data validator for JavaScript. From 16.0.0 until 17.13.6 and 18.2.5, the @hapi/joi package through 17.1.1 and the successor joi package contain prototype pollution in lib/messages.js, where exports.compile() and exports.merge() reuse inherited objects for attacker-controlled language keys supplied through messages(), message(), prefs({ messages }), Joi.extend({ messages }), or rule({ message }). A language key named __proto__ writes properties onto Object.prototype, and constructor writes to the Object function's static properties. A consuming application that gates on the presence of an inherited property can take the wrong branch for every inspected object. The flaw is not reachable from data that joi validates and requires an application to feed untrusted input directly into schema-construction configuration. This issue is fixed in joi versions 17.13.6 and 18.2.5; no fixed @hapi/joi version is available.

CVE-2026-84367 Low · 3.7 CWE-1321 Sep 1, 2026

joi: object().rename() with a template target can set the validated object's prototype

joi is a schema description language and data validator for JavaScript. From 16.0.0 until 17.13.5 and 18.2.4, joi's lib/types/keys.js internals.rename() implementation used by object().rename() permits a schema that renames keys with a regular-expression source and a Joi.expression() or Joi.x() target that interpolates the pattern's own match data, combined with { multiple: true }, to derive a target from an attacker-controlled input key. An attacker can send x-__proto__ with an object value, causing the target to render as __proto__ and set the prototype of the object returned by validate() instead of creating an own key. The global Object.prototype is not modified, so the effect is confined to the object returned by that validation call. Static-string targets and schemas using the default { multiple: false } are not affected. This issue is fixed in versions 17.13.5 and 18.2.4.

CVE-2026-82257 Medium · 4.3 CWE-1321 Aug 28, 2026

SvelteKit before 2.69.1 Prototype Pollution via File Input

SvelteKit versions before 2.69.1 contain a prototype pollution vulnerability in remote form functions with file input fields that accept arbitrary user-controlled path names. Attackers can manipulate the deletion path to remove methods on the prototype, potentially disabling application functionality.

CVE-2026-78207 Critical · 9.4 CWE-1321 Aug 23, 2026

exceljs through 4.4.0 Prototype Pollution via deepMerge Reached From Note Serialization

exceljs through 4.4.0 contains a prototype pollution vulnerability in the deepMerge helper that fails to reject __proto__, constructor, or prototype keys when merging note objects. Attackers can assign parsed JSON with a malicious __proto__ property to cell notes, modifying Object.prototype and affecting all plain objects created in the process.

CVE-2026-18420 High · 8.8 CWE-1321 Aug 20, 2026

RCE via Prototype Pollution in OpenSearch Dashboards

Improper input validation in the Time Series Visual Builder (TSVB) plugin in OpenSearch Dashboards allows an authenticated remote user to execute arbitrary code on the server via a crafted JSON payload to the metrics visualization API endpoint. This issue is a form of prototype pollution that enables remote code execution. To remediate this issue, users should upgrade to OpenSearch Dashboards 3.8 or later.

CVE-2026-77083 Medium · 5.9 CWE-1321 Aug 20, 2026

n8n before 1.123.69 Code Node Sandbox Escape via Function.prototype Pollution

n8n is a workflow automation platform. In versions prior to 1.123.69, 2.33.4, and 2.34.1, the JavaScript Code node's VM sandbox did not freeze the sandbox's Function.prototype, allowing an authenticated user with the ability to create and execute workflows to pollute it from within a Code node execution and recover a reference to the host's globalThis, resulting in a sandbox escape. The full exploit chain additionally depends on specific modules being available as allowlisted imports in the deployment's configuration. The issue is fixed in versions 1.123.69, 2.33.4, and 2.34.1.

CVE-2026-23929 Medium · 5.4 CWE-1321 Aug 18, 2026

Prototype pollution leading to stored XSS

Prototype pollution vulnerability in searchParamsToObject() is leading to a persistent XSS in Maps. URL parameter processing was not filtering dangerous properties like __proto__, combined with jQuery's unsafe element creation that traversed the prototype chain.

CVE-2026-71553 High · 7.1 CWE-1321 Aug 17, 2026

ApostropheCMS: 2nd-order prototype pollution via PATCH leading to single-request persistent DoS

ApostropheCMS is an open-source Node.js content management system. In 4.32.0 and earlier, PATCH /api/v1/article/:id accepts the inherited path toString.call and passes it through the utility module to apos.util.set() and apos.util.get(), allowing an authenticated editor to overwrite the shared Object.prototype.toString function's call property and cause a persistent process-wide denial of service until restart.

CVE-2026-73654 High · 8.5 CWE-1321 Aug 13, 2026

Trigger.dev: Prototype pollution via run metadata operations → process-wide cross-tenant DoS

Trigger.dev is a platform for building and deploying fully managed AI agents and workflows. From 3.3.8 until 4.5.6, the PUT /api/v1/runs/:runId/metadata endpoint passes attacker-controlled operation.key values to new JSONHeroPath(operation.key).set(newMetadata, value) in packages/core/src/v3/runMetadata/operations.ts without rejecting dangerous constructor and prototype path segments. A caller with a normal environment API key can pollute Object.prototype in the shared webapp process, corrupting Prisma queries and Prometheus labels, breaking other tenants' worker authentication, and causing a process-wide denial of service. This issue is fixed in version 4.5.6.

CVE-2026-73647 Medium · 5.6 CWE-1321 Aug 13, 2026

Quasar Framework: Prototype pollution in Quasar extend() utility

Quasar Framework is a framework for building high-performance Vue.js user interfaces. Prior to 2.22.0, the public extend() utility in ui/src/utils/extend/extend.js recursively copied attacker-controlled object keys during extend(true, target, source) deep merges without rejecting an own __proto__ property. The merge could descend into the prototype object and write attacker-controlled properties to Object.prototype in the same JavaScript process. Applications that passed user-controlled or partially user-controlled objects to extend() could experience logic bypass, unsafe default-option injection, denial of service, or other application-specific impact when polluted properties were later consumed. This issue is fixed in version 2.22.0.

CVE-2026-73562 Medium · 6.5 CWE-1321 Aug 13, 2026

Mongoose: Prototype pollution in the update casting via __proto__-prefixed dotted path (Schema._getSchema/path getter)

Mongoose is a MongoDB object modeling tool designed to work in an asynchronous environment. Prior to 6.13.10, 7.8.10, 8.24.1, and 9.7.2, passing a user-controlled update such as MyModel.updateOne(filter, req.body) can exploit Mongoose update casting with a __proto__.x dotted path under $set. Schema.prototype.path and Schema.prototype._getPathType can treat inherited properties of schema.paths and schema.nested as schema types, allowing the casting process to set $fullPath and $parentSchemaDocArray on Object.prototype before throwing. This prototype pollution makes those properties visible on newly created objects and can cause application integrity and availability impacts. This issue is fixed in versions 6.13.10, 7.8.10, 8.24.1, and 9.7.2.

CVE-2026-72769 High · 8.1 CWE-1321 Aug 11, 2026

n8n before 1.123.67 Prototype Pollution via VM Expression Engine

n8n before 1.123.67, 2.31.5, and 2.32.1 contains a prototype pollution vulnerability in the VM expression engine. An authenticated user able to create or edit a workflow expression can abuse the engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process (a sandbox escape), leading to a denial of service. Both self-hosted and cloud instances running the VM expression engine are affected.