fastify vulnerable to Body Schema Validation Bypass via Leading Space in Content-Type Header_CVE-2026-33806

{
    "lastseen": "",
    "description": "Impact:\n\nFastify applications using schema.body.content for per-content-type body validation can have validation bypassed entirely by prepending a space to the Content-Type header. The body is still parsed correctly but schema validation is skipped.\n\nThis is a regression introduced in fastify >= 5.3.2 by the fix for CVE-2025-32442\n\nPatches:\n\nUpgrade to fastify v5.8.5 or later.\n\nWorkarounds:\n\nNone. Upgrade to the patched version.",
    "published": "2026-04-15T00:14:02.376Z",
    "modified": "2026-04-15T00:14:02.376Z",
    "type": "cve",
    "title": "fastify vulnerable to Body Schema Validation Bypass via Leading Space in Content-Type Header",
    "source": "openjs",
    "references": "https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc\nhttps://cna.openjsf.org/security-advisories.html",
    "id": "CVE-2026-33806",
    "bulletinFamily": "",
    "cwe": [
        "CWE-1287"
    ],
    "cvelist": null,
    "sourceData": "fastify fastify 5.3.2",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "fastify",
    "version": "5.3.2",
    "vendor": "fastify",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}