CVE-2026-128344

Description

ExcelJS through 4.4.0 contains a memory exhaustion vulnerability that allows attackers to crash applications by supplying a workbook with an unbounded image anchor column in the drawing part. Attackers can set an anchor column such as 300000000 in xl/drawings/drawing1.xml so reading getImages() anchor positions makes Worksheet.getColumn allocate millions of Column objects and abort with a heap out-of-memory error.

References

• https://github.com/exceljs/exceljs
• https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/anchor.js#L40-L64
• https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L243-L261
• https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-cqmf-h7c5-g7xx
• https://www.vulncheck.com/advisories/exceljs-through-4.4.0-memory-exhaustion-via-oversized-image-anchor-column