---
id: CVE-2026-103036
title: >-
  oRPC is a tool that helps build APIs that are end-to-end type-safe and adhere
  to OpenAPI standards
summary: >-
  oRPC is a tool that helps build APIs that are end-to-end type-safe and adhere
  to OpenAPI standards. Prior to 1.14.9, the @orpc/json-schema
  SmartCoercionPlugin uses JsonSchemaCoercer to collect object properties in a
  plain object and to r…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-915
  - CWE-1321
vendor: middleapi
product: orpc
affected:
  - orpc < 1.14.9
published: '2026-10-02'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T20:16:59.567'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-103036'
references:
  - url: >-
      https://github.com/middleapi/orpc/commit/8a352622e756e8956311f5836cd5c5b9219c0666
    label: security-advisories@github.com
  - url: 'https://github.com/middleapi/orpc/pull/1726'
    label: security-advisories@github.com
  - url: 'https://github.com/middleapi/orpc/releases/tag/v1.14.9'
    label: security-advisories@github.com
  - url: 'https://github.com/middleapi/orpc/security/advisories/GHSA-4h5r-cv8j-4456'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-02T22:33:09.842Z'
---

## Overview

oRPC is a tool that helps build APIs that are end-to-end type-safe and adhere to OpenAPI standards. Prior to 1.14.9, the @orpc/json-schema SmartCoercionPlugin uses JsonSchemaCoercer to collect object properties in a plain object and to resolve schema.properties entries through the prototype chain. A remote client that can reach a procedure with an object input schema can supply __proto__ to replace the prototype of the single coerced request object, or supply Object.prototype member names such as constructor and toString so inherited values are treated as sub-schemas and pass the coercer's satisfaction check. Attacker-controlled inherited properties can consequently affect handler, Object.assign, or configuration lookups, while legitimate __proto__ properties are dropped. The global Object.prototype, unrelated objects, other requests, and other users are not modified, and downstream schema validation still runs. This issue is fixed in version 1.14.9.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.