# CVE-2026-116866: Extra Fees Plugin for WooCommerce PHP object injection

Source: https://junglewise.ai/threats/cve-2026-116866-contributor-php-object-injection-in-extra-fees-plugin-for  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-116866 · Severity: high · CVSS 8.8 · Published 2026-10-29

The Extra Fees Plugin for WooCommerce, used by online stores to add custom fees at checkout, contains a PHP object injection flaw that allows authenticated contributors to execute arbitrary code on the server. An attacker with contributor-level access could compromise the website and potentially steal customer data or inject malware into transactions.

Vendors: [WooCommerce](https://junglewise.ai/threats/vendors/woocommerce).

## Quick answers

**Is CVE-2026-116866 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116866 being exploited in the wild.

**How severe is CVE-2026-116866?** High severity, with a CVSS score of 8.8, published 29 October 2026.

**Which products and versions are affected?** WooCommerce Extra Fees Plugin for WooCommerce through 4.4.0.

**Is there a fix for CVE-2026-116866?** No fixed version is recorded yet. Patchstack has issued a mitigation rule to block attacks until an official patch is available. As an immediate action, contact your hosting provider or web developer to remove or disable the plugin until a patch is released. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-116866 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-116866?** Check whether you run WooCommerce Extra Fees Plugin for WooCommerce at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix


Patchstack has issued a mitigation rule to block attacks until an official patch is available. As an immediate action, contact your hosting provider or web developer to remove or disable the plugin until a patch is released.

## Technical details

The vulnerability is a PHP object injection flaw in versions up to 4.4.0 that can be exploited by an authenticated contributor-level user. Object injection allows manipulation of serialized data to instantiate and invoke arbitrary PHP objects, leading to remote code execution on the server. No official patch is currently available.

## Affected products

- WooCommerce Extra Fees Plugin for WooCommerce through 4.4.0

## Timeline

- 2026-10-29: disclosed
- 2026-09-17: other: Vulnerability reported by Patchstack

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/woo-conditional-product-fees-for-checkout/vulnerability/wordpress-extra-fees-plugin-for-woocommerce-plugin-4-4-0-php-object-injection-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/woo-conditional-product-fees-for-checkout/vulnerability/wordpress-extra-fees-plugin-for-woocommerce-plugin-4-4-0-php-object-injection-vulnerability?_s_id=cve)