CVE-2026-78206
exceljs through 4.4.0 Uncontrolled Resource Consumption via Unbounded xlsx Decompression
- State
- Published
- Severity
- 8.7 High
- Published
- Aug 24, 2026
- Updated
- Aug 29, 2026
- Reserved
- Aug 24, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 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 | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
Affected Products
| Product | Versions |
|---|---|
exceljsexceljs |
|
References
- https://github.com/exceljs/exceljsproduct
- GitHub Security Advisory (GHSA-7cvf-3r55-r39q)third-party-advisory
- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xlsx.js#L257-L281technical-description
- VulnCheck Advisory: exceljs through 4.4.0 Uncontrolled Resource Consumption via Unbounded xlsx Decompressionthird-party-advisory
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