{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-78206",
        "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "state": "PUBLISHED",
        "assignerShortName": "VulnCheck",
        "dateReserved": "2026-08-24T00:15:01.655Z",
        "datePublished": "2026-08-24T00:30:46.462Z",
        "dateUpdated": "2026-08-24T00:30:46.462Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
                "shortName": "VulnCheck",
                "dateUpdated": "2026-08-24T00:30:46.462Z"
            },
            "datePublic": "2026-08-23T00:00:00.000Z",
            "title": "exceljs through 4.4.0 Uncontrolled Resource Consumption via Unbounded xlsx Decompression",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "exceljs-hardened before 5.0.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "Improper Handling of Highly Compressed Data (Data Amplification)",
                            "cweId": "CWE-409",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "exceljs",
                    "product": "exceljs",
                    "collectionURL": "https://www.npmjs.com/package/exceljs",
                    "packageName": "exceljs",
                    "packageURL": "pkg:npm/exceljs",
                    "defaultStatus": "unaffected",
                    "versions": [
                        {
                            "version": "0",
                            "lessThanOrEqual": "4.4.0",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:exceljs_project:exceljs:*:*:*:*:*:*:*:*",
                                    "versionEndIncluding": "4.4.0"
                                }
                            ]
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "cvssV4_0": {
                        "version": "4.0",
                        "vectorString": "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",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "HIGH",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 8.7,
                        "baseSeverity": "HIGH"
                    }
                },
                {
                    "format": "CVSS",
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "scope": "UNCHANGED",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "availabilityImpact": "HIGH",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "references": [
                {
                    "url": "https://github.com/exceljs/exceljs",
                    "tags": [
                        "product"
                    ]
                },
                {
                    "url": "https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-7cvf-3r55-r39q",
                    "tags": [
                        "third-party-advisory"
                    ]
                },
                {
                    "url": "https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xlsx.js#L257-L281",
                    "tags": [
                        "technical-description"
                    ]
                },
                {
                    "name": "VulnCheck Advisory: exceljs through 4.4.0 Uncontrolled Resource Consumption via Unbounded xlsx Decompression",
                    "tags": [
                        "third-party-advisory"
                    ],
                    "url": "https://www.vulncheck.com/advisories/exceljs-through-uncontrolled-resource-consumption-via-unbounded-xlsx-decompression"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Matéo Florian Callec",
                    "type": "finder"
                }
            ],
            "x_generator": {
                "engine": "vulncheck-endgame"
            }
        }
    }
}