{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-126356",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-11-10T21:12:01.227Z",
        "datePublished": "2026-11-12T22:16:37.256Z",
        "dateUpdated": "2026-11-12T22:17:35.051Z"
    },
    "containers": {
        "cna": {
            "title": "Hono: `validator('form')` skips validation for `multipart/form-data` requests with extra parameters",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-20",
                            "lang": "en",
                            "description": "CWE-20: Improper Input Validation",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1471",
                            "lang": "en",
                            "description": "CWE-1471: Insufficiently Controlled Parser Differential",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/honojs/hono/security/advisories/GHSA-4h7h-rv7c-7m2v",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/honojs/hono/security/advisories/GHSA-4h7h-rv7c-7m2v"
                },
                {
                    "name": "https://github.com/honojs/hono/commit/d88fab372415277a9e540e895650943dd08eef4a",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/honojs/hono/commit/d88fab372415277a9e540e895650943dd08eef4a"
                },
                {
                    "name": "https://github.com/honojs/hono/releases/tag/v4.13.16",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/honojs/hono/releases/tag/v4.13.16"
                }
            ],
            "affected": [
                {
                    "vendor": "honojs",
                    "product": "hono",
                    "versions": [
                        {
                            "version": ">= 4.5.1, < 4.13.16",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-11-12T22:17:35.051Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Hono is a Web application framework that provides support for any JavaScript runtime. From 4.5.1 until 4.13.16, validator('form') uses a strict whole-header pattern that fails to recognize multipart/form-data when its Content-Type includes another legal parameter or extra whitespace after a semicolon. The validation callback receives an empty object even though c.req.parseBody() or c.req.formData() can still parse and expose all submitted fields to the handler. An unauthenticated client can therefore bypass allow-list or required-field checks when the application relies on the form validator and its callback accepts an empty object. application/x-www-form-urlencoded requests are not affected. This issue is fixed in version 4.13.16."
                }
            ],
            "source": {
                "advisory": "GHSA-4h7h-rv7c-7m2v",
                "discovery": "UNKNOWN"
            }
        }
    }
}