Vaultwarden: Cross-Org Group Binding Enables Unauthorized Read And Write Access Into Another Organization_CVE-2026-43912

{
    "lastseen": "",
    "description": "Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.5, Vaultwarden does not enforce that a groups_users.users_organizations_uuid entry belongs to the same organization as groups.groups_uuid, or a collections_groups.collections_uuid entry belongs to the same organization as collections_groups.groups_uuid. Multiple organization group-management endpoints accept arbitrary MembershipId and CollectionId values and persist them directly without verifying org consistency. This lets an attacker who is Admin in Organization A, and only a low-privileged member in Organization B bind their Org B membership UUID into an Org A group, then use that foreign group relationship to gain unauthorized access to Org B vault data. With an accessAll=true Org A group, the attacker can make /api/sync and /api/ciphers enumerate Org B ciphers. Once those unauthorized sync results reveal Org B collection IDs, the attacker can also bind those foreign collection IDs to the Org A group and turn the same flaw into write access over Org B items. This vulnerability is fixed in 1.35.5.",
    "published": "2026-05-11T21:56:30.108Z",
    "modified": "2026-05-11T21:56:30.108Z",
    "type": "cve",
    "title": "Vaultwarden: Cross-Org Group Binding Enables Unauthorized Read And Write Access Into Another Organization",
    "source": "GitHub_M",
    "references": "https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-569v-845w-g82p",
    "id": "CVE-2026-43912",
    "bulletinFamily": "",
    "cwe": [
        "CWE-285"
    ],
    "cvelist": null,
    "sourceData": "dani-garcia vaultwarden < 1.35.5",
    "sourceHref": "",
    "cvss": {
        "score": 8.7,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/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": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "vaultwarden",
    "version": "< 1.35.5",
    "vendor": "dani-garcia",
    "ai_description": "Cross-Org Group Binding vulnerability allowing unauthorized read and write access to another organization's vault data",
    "ai_severity": "High",
    "ai_vendor": "dani-garcia",
    "ai_product": "Vaultwarden",
    "ai_version": "< 1.35.5",
    "ai_score": 8.7
}