kin-openapi: Incomplete Fix for GHSA-p6wj-qrr4-pgh5: Three Unpatched nil-Items Panic Paths in openapi3filter

{
  "id": "4dadcbcfb4afa975836a6d3cecec30c2ab38d1308c91d8cf8051cda93b5e2362",
  "url": "https://osv.dev/vulnerability/GHSA-vrcc-3ch7-hppw",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "kin-openapi: Incomplete Fix for GHSA-p6wj-qrr4-pgh5: Three Unpatched nil-Items Panic Paths in openapi3filter",
    "summary": "## Summary The fix for GHSA-p6wj-qrr4-pgh5 addressed a nil-pointer dereference that occurs when an OpenAPI 3.1 array schema omits the `items` keyword (which is legal under JSON Schema 2020-12). That fix patched three decoder paths: the standalone `parseArray` function, the top-level array check in `UrlencodedBodyDecoder`, and `MultipartBodyDecoder`. Three additional crash paths were missed. All of them reach the unguarded `urlValuesDecoder.parseArray` method (`openapi3filter/req_resp_decoder.go:576`) or the unguarded array branch in `buildResObj` (line 1015): 1. **Query parameters** with `type: array` and no `items`. 2. **deepObject** query parameters containing an array property with no `items`. 3. **URL-encoded request bodies** where the array lives inside an `allOf` / `anyOf` / `oneOf` sub-schema. This path bypasses the guard added by the GHSA-p6wj-qrr4-pgh5 fix, because that guard only inspects top-level properties. Each path is triggerable by an unauthenticated client and produces a deterministic nil-pointer panic during request validation. ## Details ### Root Cause The three paths patched for GHSA-p6wj-qrr4-pgh5 each received a nil-`items` guard: ```go // standalone parseArray (line 1143) -- GUARDED func parseArray(raw []string, schemaRef *openapi3.SchemaRef) ([]any, error) { if schemaRef.Value.Items == nil || schemaRef.Value.Items.Value == nil { ... } // UrlencodedBodyDecoder top-level property loop (line 1441) -- GUARDED if propSchema.Value.Items == nil || propSchema.",
    "evidence": "osv:GHSA-vrcc-3ch7-hppw",
    "products": [
      {
        "name": {
          "value": "github.com/getkin/kin-openapi",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.149.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-vrcc-3ch7-hppw",
      "aliases": [
        "CVE-2026-100353",
        "GHSA-vrcc-3ch7-hppw"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.136.0"
                },
                {
                  "fixed": "0.149.0"
                }
              ]
            }
          ],
          "package": {
            "name": "github.com/getkin/kin-openapi",
            "purl": "pkg:golang/github.com/getkin/kin-openapi",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-vrcc-3ch7-hppw/GHSA-vrcc-3ch7-hppw.json"
          }
        }
      ],
      "modified": "2026-10-15T20:30:03.597762548Z",
      "provider": "osv",
      "references": [
        "https://github.com/getkin/kin-openapi/security/advisories/GHSA-vrcc-3ch7-hppw",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-100353",
        "https://github.com/getkin/kin-openapi/commit/9814d1f2b212f3508bf52296aa9e248b2122a5a9",
        "https://github.com/getkin/kin-openapi",
        "https://github.com/getkin/kin-openapi/releases/tag/v0.149.0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-476"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-15T17:17:07Z",
        "github_reviewed_at": "2026-10-15T20:20:47Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-100353",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 336036,
  "published_at": "2026-10-15T20:20:47+00:00"
}