# CVE-2026-100348: kin-openapi spec loader panics on a self-referential additionalProperties $ref (nil-pointer DoS)

> An attacker can cause a denial of service by providing a malicious OpenAPI document with a self-referential additionalProperties reference, crashing the application using kin-openapi.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** CLEANSTART-2026-IX43847, DEBIAN-CVE-2026-100348, ECHO-9e48-c71d-7876, GHSA-mh7x-f8wq-4jhx, MINI-2342-349w-x2vw, MINI-23wg-pgj4-g8jg, MINI-2mh5-69cr-24q8, MINI-2w3w-6r9m-5wrw, MINI-337p-82g6-ch68, MINI-3p3f-5frg-j7vh, MINI-45c9-c9rf-m4pp, MINI-4c4f-3r52-mcpf, MINI-4g94-jmh6-gv4r, MINI-4pgf-fhfc-jwcw, MINI-53r5-rj49-mh3p, MINI-5hj4-2qwp-f29p, MINI-6498-h5mg-fc4v, MINI-6qrf-f3hm-4wxx, MINI-87cq-m9v2-fq92, MINI-8qw4-hq95-792w, MINI-9226-jwmh-xm29, MINI-fj5q-jvq8-5hxg, MINI-g78v-4vqw-cgmp, MINI-gf4p-wp9g-4fjm, MINI-gvhp-xr79-xcj7, MINI-h6mv-4hq9-x9q6, MINI-hp2v-8f7m-4pxq, MINI-mrvf-w46x-xhp8, MINI-q238-8w7r-3mg8, MINI-q2hp-p4gm-838p, MINI-r3g9-3c54-cq93, MINI-vrg2-6jxh-j84f, MINI-w973-m628-mmh4, MINI-wjc8-9m4m-2xqx, MINI-x86r-xrpx-6x8g, MINI-x9c3-v22w-95m4, UBUNTU-CVE-2026-100348

## What is CVE-2026-100348?

CVE-2026-100348 is a medium-severity vulnerability in getkin kin-openapi, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

kin-openapi is a Go project for handling OpenAPI files. Prior to 0.145.0, openapi3.Loader can dereference a nil SchemaRef.Value while resolving a self-referential additionalProperties JSON Reference such as a schema that points to its own additionalProperties member. Loading an attacker-controlled OpenAPI document through LoadFromData, LoadFromFile, or LoadFromURI reaches resolveComponent before document validation and can panic the loading process. Resolved additionalProperties schemas and ordinary recursive schemas do not take the vulnerable nil-value path. This issue is fixed in version 0.145.0.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-100348?

2 open source packages ship an affected version, including github.com/getkin/kin-openapi.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/getkin/kin-openapi` | Go | All versions | 0.145.0 |
| `github.com/getkin/kin-openapi` | Go | All versions | 0.145.0 |

## How do I fix CVE-2026-100348?

Upgrade github.com/getkin/kin-openapi to 0.145.0 or later.

## Is CVE-2026-100348 being exploited?

There is no known exploitation of CVE-2026-100348 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100348 and fix it if it is affected.

What it is: CVE-2026-100348 is a medium-severity vulnerability in getkin kin-openapi, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-100348 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/getkin/kin-openapi (Go): affected all versions; fixed in 0.145.0
- github.com/getkin/kin-openapi (Go): affected all versions; fixed in 0.145.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-100348/ (Markdown: https://insights.sbomify.com/CVE-2026-100348/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100348
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100348
- OSV: https://osv.dev/vulnerability/CVE-2026-100348

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-100348/
Summaries are generated and may contain mistakes; the official description above is the record.