CVE-2026-128345

MEDIUM 5.3

ExcelJS through 4.4.0 ReDoS via slideFormula Shared Formula Translation

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

ExcelJS through 4.4.0 contains a regular expression denial of service vulnerability in slideFormula in lib/utils/shared-formula.js when translating shared formulas to child cells. Attackers can supply a crafted spreadsheet with very long master formulas, such as runs of hyphens, causing quadratic regex backtracking that blocks the Node.js event loop.

CWE	CWE-1333
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:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

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-pr65-54q8-vhqm github.com: https://github.com/exceljs/exceljs/blob/v4.4.0/lib/utils/shared-formula.js#L4-L12 vulncheck.com: https://www.vulncheck.com/advisories/exceljs-through-4.4.0-redos-via-slideformula-shared-formula-translation

Credits

Matéo Florian Callec