{"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-2026-128339","cwes":["CWE-770"],"description":"ExcelJS through 4.4.0 contains a memory exhaustion vulnerability in Worksheet._parseMergeCells that allows attackers to crash applications by supplying unbounded mergeCell ranges. Attackers can craft a small workbook with a mergeCell ref like A1:XFD1048576, causing xlsx.load() to create billions of Row and Cell objects and abort the process.","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":1794565094223,"publishedAt":1794562416382,"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-wh3v-83h4-rwwq"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L613-L632"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L895-L901"},{"source":"CNA: VulnCheck","tags":["issue-tracking"],"url":"https://github.com/exceljs/exceljs/issues/3107"},{"source":"CNA: VulnCheck","tags":["issue-tracking","patch"],"url":"https://github.com/exceljs/exceljs/pull/3114"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/exceljs-through-4.4.0-memory-exhaustion-via-oversized-merged-cell-range"},{"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#L613-L632"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L895-L901"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/issues/3107"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/exceljs/exceljs/pull/3114"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-wh3v-83h4-rwwq"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/exceljs-through-4.4.0-memory-exhaustion-via-oversized-merged-cell-range"}],"remediation":[{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/exceljs/exceljs/pull/3114"}],"revision":"20d7f6fa902c0014048a2848c483c50dfc33781888125ff5326c63db346327f6","sources":[{"modifiedAt":1794562416382,"name":"CNA: VulnCheck","retrievedAt":1794564869670,"url":"https://www.cve.org/CVERecord?id=CVE-2026-128339"},{"modifiedAt":1794565094223,"name":"NVD","retrievedAt":1794572258716,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-128339"}],"ssvc":null,"status":"published","title":"ExcelJS through 4.4.0 Memory Exhaustion via Oversized Merged Cell Range","updatedAt":1794572258716}