GHSA-2vgm-9qpx-xwqxHighCVSS 7.0
ExcelJS through 4.4.0 contains a prototype pollution vulnerability in mergeConditionalFormattings...
🔗 CVE IDs covered (1)
📋 Description
ExcelJS through 4.4.0 contains a prototype pollution vulnerability in mergeConditionalFormattings that allows attackers to modify Object.prototype by supplying an x14:cfRule id of proto. Attackers can craft an xlsx file that, when loaded with xlsx.load(), sets properties such as type, direction, border and cfvo on every object in the process until it restarts.
🔗 References (7)
- https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-86ch-m4gp-r5xf
- https://nvd.nist.gov/vuln/detail/CVE-2026-128337
- https://github.com/exceljs/exceljs
- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/worksheet-xform.js#L34-L42
- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/worksheet-xform.js#L55-L74
- https://www.vulncheck.com/advisories/exceljs-through-4.4.0-prototype-pollution-via-x14-conditional-formatting-rule-id
- https://github.com/advisories/GHSA-2vgm-9qpx-xwqx