CVE-2026-128346

HIGH 7.5

ExcelJS through 4.4.0 Resource Exhaustion via Streaming WorkbookReader Temporary Files

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

ExcelJS through 4.4.0 contains a resource leak vulnerability in the streaming WorkbookReader.parse that leaves temporary files and open descriptors when sheet parsing fails or iteration stops early. Attackers can repeatedly upload malformed multi-sheet workbooks with worksheets placed before xl/sharedStrings.xml to fill the temporary directory and exhaust file descriptors.

CWE	CWE-459
Vendor	exceljs
Product	exceljs
Published	Nov 13, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

exceljs / exceljs

0 ≤ 4.4.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/exceljs/exceljs github.com: https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-mp7v-gxhv-42h2 github.com: https://github.com/exceljs/exceljs/blob/v4.4.0/lib/stream/xlsx/workbook-reader.js#L111-L128 github.com: https://github.com/exceljs/exceljs/blob/v4.4.0/lib/stream/xlsx/workbook-reader.js#L140-L149 vulncheck.com: https://www.vulncheck.com/advisories/exceljs-through-4.4.0-resource-exhaustion-via-streaming-workbookreader-temporary-files

Credits

Matéo Florian Callec