{"affected":[{"defaultStatus":"unaffected","ecosystem":"npm","packageName":"exceljs","product":"exceljs","source":"CNA: VulnCheck","vendor":"exceljs","versions":[{"lessThanOrEqual":"4.4.0","status":"affected","version":"0","versionType":"semver"}]}],"cveId":"CVE-2026-128342","cwes":["CWE-606"],"description":"ExcelJS through 4.4.0 contains a denial of service vulnerability that allows attackers to block the event loop by supplying an unbounded sheetId in xl/workbook.xml. Attackers can provide a workbook with a huge sheetId, making the sparse worksheet array walk stall worksheets, getWorksheet and writeBuffer for seconds.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":8.7,"severity":"high","source":"CNA: VulnCheck","vector":"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","version":"4.0"},{"score":7.5,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},{"score":8.7,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","version":"4.0"},{"score":7.5,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1794565094670,"publishedAt":1794562414387,"references":[{"source":"CNA: VulnCheck","tags":["product"],"url":"https://github.com/exceljs/exceljs"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-9vv6-5g3h-prg5"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/workbook.js#L200-L206"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/workbook.js#L119-L125"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-worksheet-sheetid"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/workbook.js#L119-L125"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/workbook.js#L200-L206"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-9vv6-5g3h-prg5"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-worksheet-sheetid"}],"remediation":[],"revision":"74fd3468c87d35385e7607d648789433c19698cc0fbaedc6b2b029915de40ca2","sources":[{"modifiedAt":1794562414387,"name":"CNA: VulnCheck","retrievedAt":1794564873025,"url":"https://www.cve.org/CVERecord?id=CVE-2026-128342"},{"modifiedAt":1794565094670,"name":"NVD","retrievedAt":1794572259210,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-128342"}],"ssvc":null,"status":"published","title":"ExcelJS through 4.4.0 Denial of Service via Oversized Worksheet sheetId","updatedAt":1794572259210}