{"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-2026-128343","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 unbounded row r attributes parsed in row-xform.js. Attackers can craft an XLSX file with a row numbered far beyond Excel's limit, making getSheetValues(), workbook writes and CSV export consume time proportional to that number.","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":1794565094823,"publishedAt":1794562413699,"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-3gm5-qxj8-89rr"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/row-xform.js#L73-L77"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L886-L893"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L571-L580"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-row-number"},{"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/worksheet.js#L571-L580"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L886-L893"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/row-xform.js#L73-L77"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-3gm5-qxj8-89rr"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-row-number"}],"remediation":[],"revision":"4fae99e42917bade743c94ea4433105068111eba2ffe6e9d827e983a172e4208","sources":[{"modifiedAt":1794562413699,"name":"CNA: VulnCheck","retrievedAt":1794564874130,"url":"https://www.cve.org/CVERecord?id=CVE-2026-128343"},{"modifiedAt":1794565094823,"name":"NVD","retrievedAt":1794572259373,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-128343"}],"ssvc":null,"status":"published","title":"ExcelJS through 4.4.0 Denial of Service via Oversized Row Number","updatedAt":1794572259373}