# CVE-2026-100354: kin-openapi uncontrolled recursion on circular allOf/anyOf/oneOf schemas

Source: https://junglewise.ai/threats/cve-2026-100354-kin-openapi-uncontrolled-recursion-on-circular-allof-anyof-oneof  
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-2026-100354 · Severity: high · CVSS 7.5 · Published 2026-10-15

kin-openapi is a library for validating API requests and responses against OpenAPI schemas. An attacker can craft a malicious OpenAPI specification with circular schema references that causes the entire process to crash with a fatal, unrecoverable stack overflow when the schema is used for request or response validation. This allows complete denial of service of any application using the library to validate untrusted schemas.

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-2026-100354 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100354 being exploited in the wild.

**How severe is CVE-2026-100354?** High severity, with a CVSS score of 7.5, published 15 October 2026.

**Which products and versions are affected?** Getkin Kin-Openapi v0.144.0 and likely earlier versions; github.com/getkin/kin-openapi (Go) < 0.149.0, SEMVER:introduced=0,fixed=0.149.0.

**Is there a fix for CVE-2026-100354?** Yes. github.com/getkin/kin-openapi (Go): upgrade to 0.149.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-100354 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-100354?** 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
  ```


## Technical details

The vulnerability exists in two runtime validation paths (visitJSON and decodeValue) that lack cycle detection when traversing allOf/anyOf/oneOf combinators, unlike the spec-time validator which has stack-based protection. A schema that references itself through these combinators triggers unbounded recursion in Go, causing a fatal stack overflow that cannot be caught by recover() and terminates the entire process including all unrelated goroutines.

## Affected products

- getkin kin-openapi v0.144.0 and likely earlier versions

## Identifiers

- CVE-2026-100354
- GHSA-g8cf-rcjf-c8cf
- GO-2026-6785

## Timeline

- 2026-10-15: disclosed: GitHub Security Advisory GHSA-g8cf-rcjf-c8cf published

## Related threats

- [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)
- [kin-openapi nil pointer dereference in query/body array decoding](https://junglewise.ai/threats/cve-2026-100353-kin-openapi-incomplete-fix-for-ghsa-p6wj-qrr4-pgh5-three)