CVE-2026-106599: SureCart Object Injection Vulnerability

CVE-2026-106599 Overview

CVE-2026-106599 is a PHP Object Injection vulnerability in the Brainstorm Force SureCart WordPress plugin. The flaw stems from deserialization of untrusted data [CWE-502] and affects all plugin versions up to and including 4.9.3. Authenticated attackers with low privileges can exploit the vulnerability over the network to achieve full compromise of the targeted WordPress site. SureCart is an e-commerce plugin used by WordPress site operators to process payments and manage digital products, making exposed sites a target for financial fraud and site takeover.

Critical Impact
Successful exploitation enables object injection that can lead to remote code execution, data exfiltration, and complete loss of site confidentiality, integrity, and availability.

Affected Products

Brainstorm Force SureCart WordPress plugin versions through 4.9.3
WordPress sites running the vulnerable surecart plugin
Any environment where untrusted users can submit input processed by the plugin's deserialization logic

Discovery Timeline

2026-10-14 - CVE-2026-106599 published to NVD
2026-10-14 - Last updated in NVD database

Technical Details for CVE-2026-106599

Vulnerability Analysis

The vulnerability is a PHP Object Injection condition triggered when the SureCart plugin deserializes untrusted input using PHP's unserialize() function or an equivalent code path. When a serialized payload is processed, PHP instantiates arbitrary classes and invokes magic methods such as __wakeup(), __destruct(), or __toString() on the resulting objects. Attackers who can reach a chain of these methods, commonly called a POP (Property-Oriented Programming) gadget chain, can turn deserialization into arbitrary code execution, file manipulation, or SQL injection.

An authenticated attacker with low privileges, such as a customer or subscriber account on a WordPress site running SureCart, can send a crafted request to the vulnerable endpoint. Because the attack vector is network-based and complexity is low, exploitation does not require user interaction or elevated permissions.

Root Cause

The root cause is the plugin accepting and deserializing attacker-controlled data without validating its structure or restricting the classes that may be instantiated. PHP's native deserialization is unsafe when applied to untrusted input, and WordPress environments typically load many plugins and libraries, expanding the available gadget surface.

Attack Vector

Exploitation requires network access to the WordPress site and a low-privileged authenticated session. The attacker submits a serialized PHP payload to an input field, request parameter, or stored value that the plugin later passes to a deserialization function. The resulting object graph triggers gadget methods that execute attacker-chosen behavior in the context of the web server process. Detailed exploitation internals are available in the Patchstack Vulnerability Report.

Detection Methods for CVE-2026-106599

Indicators of Compromise

Requests to SureCart plugin endpoints containing serialized PHP markers such as O:, a:, or s: followed by class and property definitions.
Unexpected PHP processes spawning shell commands or writing files under wp-content/uploads/ or plugin directories.
New or modified administrator accounts in WordPress, or unexpected changes to wp_options entries related to SureCart.
Outbound network connections from the web server to unknown hosts shortly after authenticated requests to SureCart URLs.

Detection Strategies

Inspect HTTP request bodies and query parameters for serialized PHP object signatures targeting SureCart routes.
Correlate low-privileged user activity with subsequent file system writes or process creation on the web host.
Review WordPress audit logs for abnormal plugin behavior, option changes, or scheduled task modifications originating from non-admin accounts.

Monitoring Recommendations

Enable verbose web server and PHP error logging on hosts running SureCart until the plugin is patched.
Forward WordPress, web server, and host telemetry to a centralized analytics platform for correlation and historical search.
Monitor for integrity changes to plugin files and the WordPress core using file integrity monitoring tooling.

How to Mitigate CVE-2026-106599

Immediate Actions Required

Update the SureCart plugin to a release later than 4.9.3 as soon as the vendor publishes a fixed version.
Audit WordPress user accounts and revoke sessions for untrusted low-privileged users on affected sites.
Review web server, PHP, and WordPress logs for evidence of exploitation attempts since the plugin was installed.

Patch Information

The advisory is tracked by Patchstack and lists SureCart versions up to and including 4.9.3 as affected. Site operators should consult the Patchstack Vulnerability Report and the Brainstorm Force SureCart changelog for the fixed version and apply the update across all WordPress sites running the plugin.

Workarounds

Deploy a web application firewall rule that blocks requests containing serialized PHP object patterns to SureCart endpoints.
Restrict account registration and limit low-privileged user creation on sites that do not require public signup.
Temporarily deactivate the SureCart plugin on sites that cannot be patched immediately and that can tolerate loss of commerce functionality.

bash

# Example WAF rule concept: block serialized PHP objects in requests to SureCart paths
# ModSecurity example
SecRule REQUEST_URI "@contains /wp-content/plugins/surecart/" \
  "chain,id:1026106599,phase:2,deny,status:403,msg:'Possible PHP Object Injection targeting SureCart CVE-2026-106599'"
  SecRule ARGS|REQUEST_BODY "@rx (?:^|[;&])(?:O|a|s):[0-9]+:" "t:none"