CVE-2026-78206 HIGH

CVE-2026-78206: exceljs through 4.4.0 Uncontrolled Resource Consumption via Unbounded xlsx Decompression

Vendor Exceljs
Product exceljs
Weakness CWE-409
Published August 24, 2026
Last update August 29, 2026
View on NVD All CVEs

CVSS base score

8.7/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS 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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

August 24, 2026 CVE published
August 29, 2026 Record updated