Fleet has a rate limiting bypass via untrusted client IP headers_CVE-2026-24000

{
    "lastseen": "",
    "description": "Fleet is open source device management software. Prior to version 4.80.1, Fleet trusted client-supplied IP address headers when determining the source IP for incoming requests. This allowed authenticated and unauthenticated clients to spoof their apparent IP address and bypass per-IP rate limiting controls. Fleet determines a client\u2019s public IP address using HTTP headers such as X-Forwarded-For, X-Real-IP, and/or True-Client-IP. These headers were trusted without validation. An attacker could supply arbitrary values in these headers, causing Fleet to treat each request as originating from a different IP address. This could allow an attacker to bypass per-IP rate limits and increase the effectiveness of brute-force or password-spraying attempts against authentication endpoints. This issue does not allow authentication bypass, privilege escalation, data exposure, or remote code execution on its own. Version 4.80.1 contains a patch. As a workaround, run Fleet behind a trusted reverse proxy or load balancer that overwrites client IP headers.",
    "published": "2026-05-14T18:56:39.139Z",
    "modified": "2026-05-14T19:41:20.490Z",
    "type": "cve",
    "title": "Fleet has a rate limiting bypass via untrusted client IP headers",
    "source": "GitHub_M",
    "references": "https://github.com/fleetdm/fleet/security/advisories/GHSA-j8h8-75h3-jg53\nhttps://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1",
    "id": "CVE-2026-24000",
    "bulletinFamily": "",
    "cwe": [
        "CWE-290"
    ],
    "cvelist": null,
    "sourceData": "fleetdm fleet < 4.80.1",
    "sourceHref": "",
    "cvss": {
        "score": 6.9,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "fleet",
    "version": "< 4.80.1",
    "vendor": "fleetdm",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}