PT-2026-6356 · Packagist · Solspace/Craft-Freeform
Published
2026-01-15
·
Updated
2026-01-15
CVSS v4.0
1.9
Low
| Vector | AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P |
Summary
Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server.
PhpOfficePhpSpreadsheetWriterHtml doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page.
Details
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PoC
Complete instructions, including specific configuration details, to reproduce the vulnerability.
Example target script:
<?php
require 'vendor/autoload.php';
$reader = PhpOfficePhpSpreadsheetIOFactory::createReader("Xlsx");
$spreadsheet = $reader->load( DIR . '/book.xlsx');
$writer = new PhpOfficePhpSpreadsheetWriterHtml($spreadsheet);
print($writer->generateHTMLAll());Save this file in the same directory:
Open index.php in a web browser. An alert should be displayed.
Impact
What kind of vulnerability is it? Who is impacted?
Full takeover of the session of users viewing spreadsheet files as HTML.
Fix
XSS
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Weakness Enumeration
Related Identifiers
Affected Products
Solspace/Craft-Freeform