exceljs through 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Exceljs Project
  • Exceljs

No data.

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References
Link Providers
https://github.com/exceljs/exceljs cve-icon cve-icon
https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xlsx.js#L257-L281 cve-icon cve-icon
https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-7cvf-3r55-r39q cve-icon cve-icon
https://www.vulncheck.com/advisories/exceljs-through-uncontrolled-resource-consumption-via-unbounded-xlsx-decompression cve-icon cve-icon
History

Sat, 29 Aug 2026 12:00:00 +0000

Type Values Removed Values Added
Description exceljs-hardened before 5.0.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service. exceljs through 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.

Wed, 26 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 24 Aug 2026 00:45:00 +0000

Type Values Removed Values Added
Description exceljs-hardened before 5.0.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.
Title exceljs through 4.4.0 Uncontrolled Resource Consumption via Unbounded xlsx Decompression
First Time appeared Exceljs Project
Exceljs Project exceljs
Weaknesses CWE-409
CPEs cpe:2.3:a:exceljs_project:exceljs:*:*:*:*:*:*:*:*
Vendors & Products Exceljs Project
Exceljs Project exceljs
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': '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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-08-24T00:30:46.462Z

Updated: 2026-08-29T11:47:57.243Z

Reserved: 2026-08-24T00:15:01.655Z

Link: CVE-2026-78206

cve-icon Vulnrichment

Updated: 2026-08-26T18:09:52.413Z

cve-icon NVD

Status : Deferred

Published: 2026-08-24T01:16:57.973

Modified: 2026-08-31T20:52:56.343

Link: CVE-2026-78206

cve-icon Redhat

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