CVE-2026-128341

Description

ExcelJS through 4.4.0 contains a resource exhaustion vulnerability in data-validations-xform.js that allows attackers to exhaust CPU and memory by supplying unbounded sqref ranges. Attackers can provide a small crafted workbook with a sqref of A1:XFD1048576 to make xlsx.load() iterate billions of addresses, blocking the event loop and crashing the process with an uncatchable out-of-memory error.

References

• https://github.com/exceljs/exceljs
• https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/data-validations-xform.js#L216-L227
• https://github.com/exceljs/exceljs/issues/3093
• https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-f689-fh93-2pm2
• https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-data-validation-sqref