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Vulnerability record

CVE-2026-128341

highCVSS 4.0 8.7Published · exceljs

The short answer

CVE-2026-128341 affects exceljs exceljs and is rated high (CVSS 8.7). It is not in CISA's Known Exploited Vulnerabilities catalog.

What it is

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.

Weakness: CWE-770.

Severity

8.7 high

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploited (CISA KEV)

Not listed

CISA lists confirmed exploitation only

EPSS, next 30 days

No score

FIRST scores CVEs within a day of publication

How it can be exploited

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Affected products

exceljs. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2026-128341 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog as of 2026-11-13.

How do I fix CVE-2026-128341?

Follow the vendor advisory in the references below. NVD lists the affected versions under its configurations.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Received. The description is NVD's text, quoted as published.

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