Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients_CVE-2026-43639

{
    "lastseen": "",
    "description": "Bitwarden Server prior to v2026.4.0 contains a missing authorization vulnerability that allows a provider service user to add an arbitrary organization to their provider via `POST /providers/{providerId}/clients/existing`, resulting in takeover of the target organization; self-hosted installations are unaffected as this endpoint is restricted to Cloud via SelfHosted(NotSelfHostedOnly = true).",
    "published": "2026-05-11T17:14:04.552Z",
    "modified": "2026-05-11T17:14:04.552Z",
    "type": "cve",
    "title": "Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients",
    "source": "VulnCheck",
    "references": "https://sanjokkarki.com.np/blog/bitwarden-provider-takeover\nhttps://github.com/bitwarden/server/releases/tag/v2026.4.0\nhttps://github.com/bitwarden/server/pull/7372\nhttps://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d\nhttps://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients",
    "id": "CVE-2026-43639",
    "bulletinFamily": "",
    "cwe": [
        "CWE-862"
    ],
    "cvelist": null,
    "sourceData": "bitwarden server 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.9,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
        "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": "server",
    "version": "0",
    "vendor": "bitwarden",
    "ai_description": "Missing authorization vulnerability allowing a provider service user to add an arbitrary organization to their provider",
    "ai_severity": "High",
    "ai_vendor": "Bitwarden",
    "ai_product": "Bitwarden Server",
    "ai_version": "< 2026.4.0",
    "ai_score": 8.9
}