{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-34388",
        "tracking": {
            "current_release_date": "2026-04-02T20:27:51.848265Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-34388",
            "initial_release_date": "2026-03-27T20:32:59.717654Z",
            "revision_history": [
                {
                    "date": "2026-03-27T20:32:59.717654Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-27T20:33:01.724756Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-27T21:16:11.478684Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-27T21:16:14.427145Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-29T00:38:14.673744Z",
                    "number": "5",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-30T12:07:50.951618Z",
                    "number": "6",
                    "summary": "Source connected.| CVE status created. (valid)| Products connected (1).| References created (12)."
                },
                {
                    "date": "2026-03-30T12:07:54.916875Z",
                    "number": "7",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-30T19:55:02.107070Z",
                    "number": "8",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-30T19:55:04.105902Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-31T14:39:23.880543Z",
                    "number": "10",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-31T14:39:25.779266Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-02T20:26:10.540012Z",
                    "number": "12",
                    "summary": "CVSS created.| Products connected (1).| Product Identifiers created (1)."
                },
                {
                    "date": "2026-04-02T20:26:12.794019Z",
                    "number": "13",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "13"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<4.81.1",
                                "product": {
                                    "name": "vers:unknown/<4.81.1",
                                    "product_id": "CSAFPID-5963606"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Fleet"
                    }
                ],
                "category": "vendor",
                "name": "Open Source"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<4.81.0",
                                "product": {
                                    "name": "vers:unknown/<4.81.0",
                                    "product_id": "CSAFPID-5944572",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "fleet"
                    }
                ],
                "category": "vendor",
                "name": "fleetdm"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-34388",
            "notes": [
                {
                    "category": "description",
                    "text": "Fleet is open source device management software. Prior to 4.81.0, a denial-of-service vulnerability in Fleet's gRPC Launcher endpoint allows an authenticated host to crash the entire Fleet server process by sending an unexpected log type value. The server terminates immediately, disrupting all connected hosts, MDM enrollments, and API consumers. Version 4.81.0 patches the issue.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34388.json"
                },
                {
                    "category": "description",
                    "text": "Fleet is open source device management software. Prior to 4.81.0, a denial-of-service vulnerability in Fleet's gRPC Launcher endpoint allows an authenticated host to crash the entire Fleet server process by sending an unexpected log type value. The server terminates immediately, disrupting all connected hosts, MDM enrollments, and API consumers. Version 4.81.0 patches the issue.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34388"
                },
                {
                    "category": "description",
                    "text": "### Summary\n\nA Denial of Service vulnerability in Fleet's gRPC Launcher endpoint allows an authenticated host to crash the entire Fleet server process by sending an unexpected log type value. The server terminates immediately, disrupting all connected hosts, MDM enrollments, and API consumers.\n\n### Impact\n\nAn attacker with access to a valid Launcher node key can send a specially crafted gRPC request to the Fleet server that triggers an unrecoverable server crash. The gRPC server lacks appropriate error recovery handling, meaning the entire Fleet process terminates rather than gracefully rejecting the malformed input.\n\nBecause the crash is instant and repeatable, an attacker could script repeated requests to prevent the server from recovering, resulting in a persistent denial of service until a patched version is deployed.\n\n### Workarounds\n\nThere is no workaround for this issue other than upgrading to a patched version.\n\n### For more information\n\nIf there are any questions or comments about this advisory:\n\nSend an email to  [security@fleetdm.com](mailto:security@fleetdm.com)\n\nJoin #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)\n\n### Credits\n\nFleet thanks @fuzzztf for responsibly reporting this issue.",
                    "title": "github - https://api.github.com/advisories/GHSA-w254-4hp5-7cvv"
                },
                {
                    "category": "other",
                    "text": "0.00042",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U",
                    "title": "CVSSV4"
                },
                {
                    "category": "other",
                    "text": "6.6",
                    "title": "CVSSV4 base score"
                },
                {
                    "category": "other",
                    "text": "4.6",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "There is product data available from source Certbundde",
                    "title": "NCSC Score top increasing factors"
                },
                {
                    "category": "other",
                    "text": "There is cwe data available from source Github, Is related to (a version of) an uncommon product, Is related to a product by vendor Open Source",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5944572",
                    "CSAFPID-5963606"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34388.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34388"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - certbundde",
                    "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0902.json"
                },
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-w254-4hp5-7cvv"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde; cveprojectv5; github; nvd",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0902.json"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0902"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-3458-r943-hmx4"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-4f9r-x588-pp2h"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-7rhw-5mpv-gp4h"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-99hj-44vg-hfcp"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-9p23-p2m4-2r4m"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-m2h6-4xpq-qw3m"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-v895-833r-8c45"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-wg7j-pcc3-h4rh"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34388"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-w254-4hp5-7cvv"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "products": [
                        "CSAFPID-5944572",
                        "CSAFPID-5963606"
                    ]
                }
            ],
            "title": "CVE-2026-34388"
        }
    ]
}