@fastify/static vulnerable to route guard bypass via encoded path separators_CVE-2026-6414

{
    "lastseen": "",
    "description": "@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.",
    "published": "2026-04-16T13:09:03.526Z",
    "modified": "2026-04-16T13:09:03.526Z",
    "type": "cve",
    "title": "@fastify/static vulnerable to route guard bypass via encoded path separators",
    "source": "openjs",
    "references": "https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p\nhttps://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr\nhttps://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92\nhttps://cna.openjsf.org/security-advisories.html",
    "id": "CVE-2026-6414",
    "bulletinFamily": "",
    "cwe": [
        "CWE-177"
    ],
    "cvelist": null,
    "sourceData": "@fastify/static @fastify/static 8.0.0",
    "sourceHref": "",
    "cvss": {
        "score": 5.9,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "@fastify/static",
    "version": "8.0.0",
    "vendor": "@fastify/static",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}