---
id: "CVE-2026-115943"
kind: "vulnerability"
aliases: ["CVE-2026-115943"]
title: "Spreadsheet::XLSX for Perl: crafted spreadsheet runs arbitrary code on parse"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["package", "perl", "spreadsheet-xlsx"]
not_affected_if: ["no-untrusted-xlsx-input", "version-0.19-or-later"]
published_at: "2026-10-29T22:17:00+00:00"
first_seen_at: "2026-10-29T22:27:06+00:00"
updated_at: "2026-10-29T22:28:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115943", "first_seen_at": "2026-10-29T22:27:06+00:00"}]
---

# Spreadsheet::XLSX for Perl: crafted spreadsheet runs arbitrary code on parse

Spreadsheet::XLSX versions before 0.19 pass number format conditions from an XLSX file into a Perl string eval while the file is parsed. A person who gets a crafted spreadsheet processed by the library can make it run arbitrary Perl code.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed version with `perl -MSpreadsheet::XLSX -e 'print $Spreadsheet::XLSX::VERSION'` or `cpanm --info Spreadsheet::XLSX`
- Search dependency manifests and lockfiles for `Spreadsheet::XLSX` to find projects that pull it in

## Fix

- Spreadsheet::XLSX: `0.19` or later (per the sources, versions before 0.19 are affected)

## Timeline

- 2026-10-29T22:27:06+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115943

## From the sources

Spreadsheet::XLSX versions before 0.19 for Perl allow code execution via string eval of number format conditions in ExcelFmt.

When a number format has a condition such as [>100], ExcelFmt chooses the format section by passing the condition and the cell value to a string eval. Both come from the workbook, and the eval runs while Spreadsheet::XLSX->new parses it.

An attacker who supplies an XLSX file can run arbitrary Perl code.

---

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