Is there a public exploit for CVE-2026-128339?

No public exploit for CVE-2026-128339 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-128339?

CVE-2026-128339 scores CVSS 8.7 (v4.0), rated high.

What does CVE-2026-128339 affect?

CVE-2026-128339 affects exceljs exceljs.

8.7 High

ExcelJS through 4.4.0 contains a memory exhaustion vulnerability in Worksheet.parseMergeCells that allows attackers to crash applications…

CVE-2026-128339

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.

Assessment

CVSS: 8.7 (v4.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 13 November 2026
Last updated: 13 November 2026
Affected: exceljs · exceljs
Assigner: VulnCheck

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

At the source

EUVD (ENISA)

References

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