Grav: Unauthenticated Path Traversal & Arbitrary File Write in FormFlash component._CVE-2026-42608

{
    "lastseen": "",
    "description": "Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories and write an index.yaml file containing attacker-controlled data. This vulnerability can lead to unauthorized modification of application behavior, potential data integrity issues, and service disruption in production environments. This vulnerability is fixed in 2.0.0-beta.2.",
    "published": "2026-05-11T15:02:15.956Z",
    "modified": "2026-05-11T15:02:15.956Z",
    "type": "cve",
    "title": "Grav: Unauthenticated Path Traversal & Arbitrary File Write in FormFlash component.",
    "source": "GitHub_M",
    "references": "https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2",
    "id": "CVE-2026-42608",
    "bulletinFamily": "",
    "cwe": [
        "CWE-22"
    ],
    "cvelist": null,
    "sourceData": "getgrav grav < 2.0.0-beta.2",
    "sourceHref": "",
    "cvss": {
        "score": 8.8,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
        "version": "4.0"
    },
    "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": "grav",
    "version": "< 2.0.0-beta.2",
    "vendor": "getgrav",
    "ai_description": "Unauthenticated Path Traversal and Arbitrary File Write vulnerability in the FormFlash component of Grav, allowing attackers to modify application behavior and disrupt service",
    "ai_severity": "High",
    "ai_vendor": "GetGrav",
    "ai_product": "Grav",
    "ai_version": "< 2.0.0-beta.2",
    "ai_score": 8.8
}