# CVE-2026-100353: kin-openapi nil pointer dereference in query/body array decoding

Source: https://junglewise.ai/threats/cve-2026-100353-kin-openapi-incomplete-fix-for-ghsa-p6wj-qrr4-pgh5-three  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-15. Updated: 2026-10-15  
License: CC BY 4.0 with a link back

CVE-2026-100353 · Severity: high · CVSS 7.5 · Published 2026-10-15

kin-openapi is a library for validating REST API requests against OpenAPI 3.1 specifications. A flaw in its request validator allows an unauthenticated client to crash the application with a specially crafted request if the API spec declares array parameters or body fields without schema definitions. On standard web servers this causes individual requests to be dropped; on other platforms or custom deployments it can crash the entire process.

Technologies: [Getkin Kin-Openapi](https://junglewise.ai/threats/technologies/kin-openapi), [github.com/getkin/kin-openapi (Go)](https://junglewise.ai/threats/technologies/github-com-getkin-kin-openapi). Vendors: [Getkin](https://junglewise.ai/threats/vendors/getkin), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-100353 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100353 being exploited in the wild.

**How severe is CVE-2026-100353?** High severity, with a CVSS score of 7.5, published 15 October 2026.

**Which products and versions are affected?** Getkin Kin-Openapi before 0.145.0 (fix unspecified in advisory); github.com/getkin/kin-openapi (Go) >= 0.136.0, < 0.149.0, SEMVER:introduced=0.136.0,fixed=0.149.0.

**Is there a fix for CVE-2026-100353?** Yes. github.com/getkin/kin-openapi (Go): upgrade to 0.149.0 or later. Until then: Until upgrade is possible, disable request validation for array parameters and URL-encoded bodies in the affected API specs, or ensure the OpenAPI spec does not declare arrays without `items` schemas. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-100353 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-100353?** Check whether you run Getkin Kin-Openapi or github.com/getkin/kin-openapi (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/getkin/kin-openapi (Go): upgrade to 0.149.0 or later

  ```sh
  go get github.com/getkin/kin-openapi@v0.149.0
  ```


Until upgrade is possible, disable request validation for array parameters and URL-encoded bodies in the affected API specs, or ensure the OpenAPI spec does not declare arrays without `items` schemas.

## Technical details

The vulnerability is a nil-pointer dereference in three code paths when decoding arrays without an `items` schema keyword: query parameters, deepObject query parameters, and URL-encoded request bodies with arrays inside `allOf`/`anyOf`/`oneOf` sub-schemas. The `urlValuesDecoder.parseArray` and `buildResObj` functions lack nil-checks before dereferencing the schema, which is legal in OpenAPI 3.1 (JSON Schema 2020-12 permits omitting `items`). An unauthenticated attacker can trigger the panic by sending a request matching the vulnerable spec pattern.

## Affected products

- getkin kin-openapi before 0.145.0 (fix unspecified in advisory)

## Identifiers

- CVE-2026-100353
- GHSA-vrcc-3ch7-hppw
- GO-2026-6800

## Timeline

- 2026-10-15: disclosed: GHSA-vrcc-3ch7-hppw published
- 2026-10-15: kev added

## Related threats

- [kin-openapi uncontrolled recursion on circular allOf/anyOf/oneOf schemas](https://junglewise.ai/threats/cve-2026-100354-kin-openapi-uncontrolled-recursion-on-circular-allof-anyof-oneof)
- [kin-openapi SecurityHandler authentication bypass via path encoding](https://junglewise.ai/threats/cve-2026-100351-kin-openapi-validationhandler-security-requirement-bypass-via)
- [kin-openapi deepObject query decoding DoS via repeated regexp compilation](https://junglewise.ai/threats/cve-2026-100350-kin-openapi-deepobject-query-decoding-repeatedly-compiles-an)
- [kin-openapi OpenAPI spec loader nil-pointer panic on self-referential additionalProperties](https://junglewise.ai/threats/cve-2026-100348-kin-openapi-spec-loader-panics-on-a-self-referential)
- [kin-openapi: Unauthenticated denial of service in legacy router](https://junglewise.ai/threats/cve-2026-100347-kin-openapi-unauthenticated-panic-dos-in-openapi3filter-legacy)