Summary
solspace/craft-freeform Vulnerable to XSS in PhpSpreadsheet HTML Writer Due to Unsanitized Styling Data
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.
\PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page.
Details
Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer.
See https://github.com/advisories/GHSA-wgmf-q9vr-vww6
PoC
Complete instructions, including specific configuration details, to reproduce the vulnerability.
Example target script:
<?php
require 'vendor/autoload.php';
$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader("Xlsx");
$spreadsheet = $reader->load(__DIR__ . '/book.xlsx');
$writer = new \PhpOffice\PhpSpreadsheet\Writer\Html($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.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-44JG-MV3H-WJ6G? GHSA-44JG-MV3H-WJ6G is a low-severity cross-site scripting (XSS) vulnerability in solspace/craft-freeform (composer), affecting versions < 4.1.23. It is fixed in 4.1.23. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of solspace/craft-freeform are affected by GHSA-44JG-MV3H-WJ6G? solspace/craft-freeform (composer) versions < 4.1.23 is affected.
- Is there a fix for GHSA-44JG-MV3H-WJ6G? Yes. GHSA-44JG-MV3H-WJ6G is fixed in 4.1.23. Upgrade to this version or later.
- Is GHSA-44JG-MV3H-WJ6G exploitable, and should I be worried? Whether GHSA-44JG-MV3H-WJ6G is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-44JG-MV3H-WJ6G is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-44JG-MV3H-WJ6G? Upgrade
solspace/craft-freeformto 4.1.23 or later.