How severe is GHSA-hwcp-2h35-p66w?

GHSA-hwcp-2h35-p66w has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-hwcp-2h35-p66w?

GHSA-hwcp-2h35-p66w affects the following packages: phpoffice/phpspreadsheet (Packagist), phpoffice/phpspreadsheet (Packagist), phpoffice/phpspreadsheet (Packagist), phpoffice/phpspreadsheet (Packagist), phpoffice/phpexcel (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-hwcp-2h35-p66w?

Update phpoffice/phpspreadsheet to 3.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hwcp-2h35-p66w is resolved across your whole dependency graph.

How do I detect GHSA-hwcp-2h35-p66w in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpoffice/phpspreadsheet. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-hwcp-2h35-p66w if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-hwcp-2h35-p66w?

O3 pinpoints whether GHSA-hwcp-2h35-p66w is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-hwcp-2h35-p66w actively exploited in the wild?

No public exploit code has been indexed for GHSA-hwcp-2h35-p66w yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-hwcp-2h35-p66w?

GHSA-hwcp-2h35-p66w has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 26th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-hwcp-2h35-p66w?

GHSA-hwcp-2h35-p66w is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-hwcp-2h35-p66w published, and has it been updated?

GHSA-hwcp-2h35-p66w was published on January 3, 2025 and was last updated on March 6, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

GHSA-hwcp-2h35-p66w

MEDIUM

PhpSpreadsheet has a Cross-Site Scripting (XSS) vulnerability of the hyperlink base in the HTML page header

Also known asCVE-2024-56411

Published

Jan 3, 2025

Updated

Mar 6, 2025

Affected

5 pkgs

Patched

4 / 5

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk26th percentile-0.56%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

5 pkgs affected

🐘phpoffice/phpspreadsheet🐘phpoffice/phpspreadsheet🐘phpoffice/phpspreadsheet🐘phpoffice/phpspreadsheet🐘phpoffice/phpexcel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Cross-Site Scripting (XSS) vulnerability of the hyperlink base in the HTML page header

Product: Phpspreadsheet Version: version 3.6.0 CWE-ID: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CVSS vector v.3.1: 5.4 (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N) CVSS vector v.4.0: 4.8 (AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N) Description: the HTML page is formed without sanitizing the hyperlink base Impact: executing arbitrary JavaScript code in the browser Vulnerable component: class PhpOffice\PhpSpreadsheet\Writer\Html, method generateHTMLHeader Exploitation conditions: a user viewing a specially generated Excel file Mitigation: additional sanitization of special characters in a string Researcher: Aleksey Solovev (Positive Technologies)

Research

The researcher discovered zero-day vulnerability Cross-Site Scripting (XSS) vulnerability of the hyperlink base in the HTML page header in Phpspreadsheet. The following code is written on the server, which translates the XLSX file into a HTML representation and displays it in the response.

Listing 8. Source code on the server

<?php

require __DIR__ . '/vendor/autoload.php';

$inputFileName = './doc/Book1.xlsx';
$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($inputFileName);
$writer = new \PhpOffice\PhpSpreadsheet\Writer\Html($spreadsheet);
print($writer->generateHTMLAll());

An attacker can embed a payload in a file property that will result in the execution of arbitrary JavaScript code. The Excel file is unpacked and a HyperlinkBase in the file is inserted into the docProps/app.xml file.

fig14

Figure 14. Embedding the payload

After the changes were made, a new archive with the xlsx extension was created. At the moment of converting the xlsx file into the HTML representation, a property is obtained that participates in the formation of a string without sanitization.

fig15

Figure 15. Generating the HTML page header using the HyperlinkBase property

After generating and displaying the HTML representation of the XLSX file, arbitrary JavaScript code will be executed. <img width="356" alt="fig16" src="https://github.com/user-attachments/assets/c3694661-31e3-4be8-9a86-6eb4dd4647b5" />

Figure 16. Executing arbitrary JavaScript code

Credit

This vulnerability was discovered by Aleksey Solovev (Positive Technologies)

Affected Packages

5 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`phpoffice/phpspreadsheet`	≥ 3.0.0&&< 3.7.0	3.7.0
🐘Packagist	`phpoffice/phpspreadsheet`	all versions	1.29.7
🐘Packagist	`phpoffice/phpspreadsheet`	≥ 2.0.0&&< 2.1.6	2.1.6
🐘Packagist	`phpoffice/phpspreadsheet`	≥ 2.2.0&&< 2.3.5	2.3.5
🐘Packagist	`phpoffice/phpexcel`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpoffice/phpspreadsheet. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update phpoffice/phpspreadsheet to 3.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hwcp-2h35-p66w is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-hwcp-2h35-p66w is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-hwcp-2h35-p66w. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

# Cross-Site Scripting (XSS) vulnerability of the hyperlink base in the HTML page header **Product**: Phpspreadsheet **Version**: version 3.6.0 **CWE-ID**: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') **CVSS vector v.3.1**: 5.4 (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N) **CVSS vector v.4.0**: 4.8 (AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N) **Description**: the HTML page is formed without sanitizing the hyperlink base **Impact**: executing arbitrary JavaScript code in the browser **Vulnerable component**: class `PhpOffice\PhpSpreadsheet\W

O3 Security · Impact-Aware SCA

Is GHSA-hwcp-2h35-p66w in your dependencies?

O3 detects GHSA-hwcp-2h35-p66w across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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