CVE-2026-56763
Hono before 4.12.7 allows __proto__ key in parseBody with dot option enabled, permitting specially crafted form field names to create object
CVSS
4.8
Medium
EPSS
0.3%
p19
KEV
—
Exploit Today
6
0-100
Published: Jul 11, 2026 · Last modified: Jul 14, 2026 · CWE-1321
0.2%EPSS · 30 days0.3%
2026-08-062026-09-02
Hono before 4.12.7 allows __proto__ key in parseBody with dot option enabled, permitting specially crafted form field names to create objects with __proto__ properties. When parsed results are merged into regular JavaScript objects using unsafe merge patterns, attackers can exploit this to achieve prototype pollution and modify object behavior.
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-824048.3 HIG—
——0TOON 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 2.3.1.1dCVE-2026-843683.7 LOW16.9%
——5joi 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.2dCVE-2026-843673.7 LOW18.8%
——6joi 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 18.2.4.2dCVE-2026-822574.3 MED10.5%
——3SvelteKit 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.4dCVE-2026-781817.3 HIG36.7%
——11A weakness has been identified in ractivejs ractive up to 1.4.4. Impacted is the function Ractive#set of the component Keypath Handler. Executing a manipulation can lead to improperly controlled modification of object prototype attributes. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.8dCVE-2026-781807.3 HIG36.7%
——11A security flaw has been discovered in alibaba-fusion next up to 1.27.34. This issue affects the function ConfigProvider.getContextProps of the file components/dialog/index.tsx of the component deepMerge. Performing a manipulation of the argument locale results in improperly controlled modification of object prototype attributes. The attack may be initiated remotely. The reported GitHub issue was closed automatically due to inactivity.10d