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Findings

CVE-2026-100348

kin-openapi is a Go project for handling OpenAPI files.

Published Oct 15, 2026 · corrected/updated Oct 16, 2026 · evidence confidence high

The defect ---------- Confirmed at HEAD (f0407d5, v0.144.0). openapi3/loader.go, inside resolveComponent's drill closure (around line 455), the case *SchemaRef branch for pathPart == "additionalProperties" dereferences c.Value.AdditionalProperties with no nil-check on c.Value: case *SchemaRef: if pathPart == "additionalProperties" { if ap := c.Value.AdditionalProperties.Has; ap != nil { // c.Value can be nil here cursor = *ap } else { cursor = c.Value.AdditionalProperties.Schema } attempted = true } When a $ref fragment drills through .../additionalProperties of a schema whose Value is still nil (a pure, not-yet-resolved $ref, or a self-reference resolved before its own Value is set), c.Value is nil and the .AdditionalProperties access panics. Input and attacker ------------------- A tiny crafted OpenAPI document, one schema, no external refs, no network: openapi: 3.0.3 info: {title: t, version: "1.0.0"} paths: {} components: schemas: A: $ref: '#/components/schemas/A/additionalProperties' Attacker model: any service or tool that loads an untrusted spec via the default openapi3.Loader (LoadFromData / LoadFromFile / LoadFromURI), e.g. a spec registry, an API-management platform ingesting user specs, a linter, or a converter. It crashes during LOAD (ResolveRefsIn), before Validate. Verification level ------------------ EXECUTED with negative controls (agent-run go test at HEAD f0407d5, including yesterday's security merge; the bug is still present). The full stack pins LoadFromData:196 -> ResolveRefsIn:274 -> resolveSchemaRef:1048 -> resolveComponent:485 -> drill:439 -> :455, propagating to main(); no recover() in loader.go/schema.go (grep + trace). Two negative controls stay clean: drilling additionalProperties of a resolved schema loads fine (the existing TestIssue376 happy path), and a normal recursive schema loads fine, so the nil Value is specifically the cause. I independently re-confirmed at HEAD that loader.go:455 dereferences c.Value.AdditionalProperties with

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-100348 is a medium public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: golang-github-getkin-kin-openapi (0.110.0-1, 0.117.0-1, 0.118.0-1); golang-github-getkin-kin-openapi (0.124.0-1, 0.135.0-1); golang-github-getkin-kin-openapi (0.124.0-1, 0.135.0-1); github.com/getkin/kin-openapi (<= 0.144.0). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 5.3, EPSS 0.4%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-476. Sources contributing to this record: cve_org, epss, github, gitlab. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Technology hubs

Debian

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 15, 2026 · NIST NVD

    Detected

    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 d

  2. Oct 15, 2026 · NIST NVD

    Updated

    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 d

  3. Oct 15, 2026 · GitHub Advisory Database

    Updated

    The defect ---------- Confirmed at HEAD (f0407d5, v0.144.0). openapi3/loader.go, inside resolveComponent's drill closure (around line 455), the case *SchemaRef branch for pathPart == "additionalProperties" dereferences c.Value.AdditionalProperties with no nil-check on c.Value: case *SchemaRef: if pathPart == "additionalProperties" { if ap := c.Value.AdditionalProperties.Has; ap != nil { // c.Value

  4. Oct 16, 2026 · OSV.dev

    Updated

    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 d

Affected

  • Debian:12 golang-github-getkin-kin-openapi0.110.0-1, 0.117.0-1, 0.118.0-1
  • Debian:13 golang-github-getkin-kin-openapi0.124.0-1, 0.135.0-1
  • Debian:14 golang-github-getkin-kin-openapi0.124.0-1, 0.135.0-1
  • go github.com/getkin/kin-openapi<= 0.144.0
  • golang github.comversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-100348

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-100348

    30-day exploitation probability 0.4%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-mh7x-f8wq-4jhx

    kin-openapi spec loader panics on a self-referential additionalProperties $ref (nil-pointer DoS)

    github.com
  • GitLab Advisory DatabasePackage advisoryCVE-2026-100348

    The defect Confirmed at HEAD (f0407d5, v0.144.0). openapi3/loader.go, inside resolveComponent's drill closure (around line 455), the case *SchemaRef branch for pathPart == "additionalProperties" dereferences c.Value.AdditionalProperties with no nil-check on c.Value: case *SchemaRef: if pathPart == "additionalProperties" { if ap := c.Value.AdditionalProperties.Has; ap != nil { // c.Value can be nil

    advisories.gitlab.com
  • NIST NVDVulnerability recordCVE-2026-100348

    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 a

    nvd.nist.gov
  • OSV.devPackage advisoryDEBIAN-CVE-2026-100348
    osv.dev

References