Vaultwarden WebAuthn credential metadata tampered before signature verification_CVE-2026-31835

{
    "lastseen": "",
    "description": "Vaultwarden is a Bitwarden-compatible server written in Rust. In versions 1.35.4 and earlier, the WebAuthn authentication flow in `validate_webauthn_login()` updates persistent credential metadata (1backup_eligible1 and 1backup_state flags1) based on unverified `authenticatorData` before signature validation is performed. An attacker who knows a user's password but cannot produce a valid WebAuthn signature can permanently modify the stored backup flags for that user's credential. If signature verification fails, the database update is not rolled back. This can result in a persistent denial of service of WebAuthn two-factor authentication for affected credentials. This issue has been fixed in version 1.35.5.",
    "published": "2026-05-05T18:51:35.457Z",
    "modified": "2026-05-05T18:51:35.457Z",
    "type": "cve",
    "title": "Vaultwarden WebAuthn credential metadata tampered before signature verification",
    "source": "GitHub_M",
    "references": "https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-x7g7-cgx5-jhx2\nhttps://github.com/dani-garcia/vaultwarden/releases/tag/1.35.5",
    "id": "CVE-2026-31835",
    "bulletinFamily": "",
    "cwe": [
        "CWE-345"
    ],
    "cvelist": null,
    "sourceData": "dani-garcia vaultwarden < 1.35.5",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
        "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": "",
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            "privilegesRequired": "",
            "userInteraction": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "vaultwarden",
    "version": "< 1.35.5",
    "vendor": "dani-garcia",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}