CVE-2026-42716: Payever WooCommerce PHP Object Injection

CVE-2026-42716 Overview

CVE-2026-42716 is an unauthenticated PHP Object Injection vulnerability in the Payever WooCommerce Gateway plugin for WordPress, affecting versions up to and including 4.8.2. The flaw stems from insecure deserialization of untrusted input [CWE-502], allowing network-based attackers to inject crafted PHP objects without authentication. Successful exploitation can lead to arbitrary code execution, data tampering, or complete site compromise when a suitable gadget chain is present in the WordPress environment.

Critical Impact
Unauthenticated attackers can trigger PHP object instantiation on vulnerable WooCommerce stores, enabling remote code execution and full confidentiality, integrity, and availability loss.

Affected Products

Payever WooCommerce Gateway plugin for WordPress, versions <= 4.8.2
WordPress sites running WooCommerce with the vulnerable plugin installed
Hosting environments exposing the plugin's endpoints to untrusted network traffic

Discovery Timeline

2026-10-10 - CVE-2026-42716 published to the National Vulnerability Database
2026-10-13 - Last updated in the NVD database

Technical Details for CVE-2026-42716

Vulnerability Analysis

The Payever WooCommerce Gateway plugin deserializes attacker-controlled input without validating or restricting the resulting object types. PHP's unserialize() function reconstructs objects along with their magic methods such as __wakeup(), __destruct(), and __toString(). When a vulnerable application processes attacker-supplied serialized data, those magic methods execute automatically against reconstructed objects.

In WordPress environments, numerous plugins and core libraries expose classes that can be chained into Property-Oriented Programming (POP) gadgets. An attacker who identifies a usable gadget chain within the target site can escalate the object injection into file writes, arbitrary function calls, or remote code execution. Because the vulnerability requires no authentication, any internet-exposed WooCommerce store running the vulnerable plugin is reachable by anonymous attackers.

Root Cause

The root cause is improper deserialization of untrusted data [CWE-502]. The plugin passes externally supplied values to a deserialization routine without allow-listing expected classes or validating input structure. PHP therefore instantiates whatever class the attacker encodes in the payload.

Attack Vector

The attack vector is network-based and unauthenticated. An attacker crafts a serialized PHP payload referencing gadget classes available in the WordPress runtime and submits it to the vulnerable plugin endpoint. See the Patchstack Vulnerability Report for additional context on the affected code path.

// No verified public exploit code is available at this time.
// Refer to the Patchstack advisory linked above for technical details.

Detection Methods for CVE-2026-42716

Indicators of Compromise

Inbound HTTP requests to Payever WooCommerce Gateway endpoints containing serialized PHP strings beginning with O:, a:, or s: tokens.
Unexpected PHP processes spawning shell commands or writing files under wp-content/uploads/ or plugin directories.
New or modified PHP files in the WordPress document root that do not correspond to plugin updates.
Outbound connections from the web server to unknown hosts following plugin requests.

Detection Strategies

Inspect web server and WAF logs for POST parameters or cookies containing PHP serialization markers directed at payever-woocommerce-gateway routes.
Monitor PHP-FPM and web process trees for anomalous child processes such as sh, bash, curl, or wget originating from the web user.
Correlate plugin request traffic with file integrity monitoring alerts on WordPress directories.

Monitoring Recommendations

Enable verbose logging on the WordPress site and forward web, application, and system logs to a centralized analytics platform for correlation.
Alert on serialization patterns in HTTP request bodies and query strings targeting WooCommerce endpoints.
Track outbound network activity from PHP workers to detect staging of secondary payloads.

How to Mitigate CVE-2026-42716

Immediate Actions Required

Identify all WordPress sites running the Payever WooCommerce Gateway plugin at version 4.8.2 or earlier and prioritize them for patching.
Update the plugin to a fixed version as published by the vendor; consult the Patchstack advisory for the current fixed release.
If a fixed version is not yet deployable, disable the plugin until remediation is applied.
Review web, application, and file integrity logs for signs of prior exploitation.

Patch Information

Upgrade the Payever WooCommerce Gateway plugin beyond version 4.8.2. Refer to the Patchstack vulnerability database entry for the authoritative patched version and vendor guidance.

Workarounds

Deactivate and remove the Payever WooCommerce Gateway plugin on sites that do not require the integration.
Deploy a Web Application Firewall rule to block requests containing PHP serialization patterns targeting plugin endpoints.
Restrict access to the WooCommerce checkout and payment callback paths to known Payever source IP ranges where feasible.
Enforce least-privilege file system permissions on the web server to limit the impact of arbitrary writes.

bash

# Example: disable the plugin via WP-CLI pending patch deployment
wp plugin deactivate payever-woocommerce-gateway
wp plugin status payever-woocommerce-gateway