CVE-2026-128339: ExcelJS through 4.4.0 Memory Exhaustion via Oversized Merged Cell Range
Vendor fix available · Affected: exceljs · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 53% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- exceljs · exceljsup to and including 4.4.0
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- exceljs
- Published
- November 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-128339 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.