All vulnerabilities
CVE-2026-103036GHSA-4h5r-cv8j-4456

@orpc/json-schema: Prototype injection in smart coercion

middleapi orpc
CVSS
6.5Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.23%Chance of exploitation activity in the next 30 days, higher than 13% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1.14.9Fixed versionGitHub
Published2 Oct 2026Updated 5 Oct 2026CVE List

What fixes it

  • 1.14.9@orpc/json-schema, npmGitHubnpm install @orpc/json-schema@1.14.9

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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.

Text from CVE List

Affected versions 2

  • orpcaffected: < 1.14.9CVE List
  • @orpc/json-schema, npm<= 1.14.8GitHub

References 4