CVE-2026-40753: EasyMeals PHP Object Injection Vulnerability

CVE-2026-40753 Overview

CVE-2026-40753 is an unauthenticated PHP Object Injection vulnerability affecting the EasyMeals WordPress theme in versions up to and including 1.5.1. The flaw is rooted in insecure deserialization of untrusted input [CWE-502]. Remote attackers can submit crafted serialized payloads without authentication, triggering object instantiation within the PHP runtime.

When a suitable POP (Property-Oriented Programming) chain exists in the WordPress core, the active theme, or co-installed plugins, exploitation can lead to arbitrary file operations, SQL injection, or remote code execution. The vulnerability is tracked by Patchstack and carries an EPSS probability of 0.308%.

Critical Impact
Unauthenticated attackers can inject PHP objects into the EasyMeals theme, potentially achieving remote code execution when a viable gadget chain is present.

Affected Products

EasyMeals WordPress theme versions <= 1.5.1
WordPress sites using the EasyMeals theme as the active or fallback theme
Environments where additional plugins expose deserialization gadget chains

Discovery Timeline

2026-06-17 - CVE-2026-40753 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-40753

Vulnerability Analysis

The vulnerability is an instance of Insecure Deserialization [CWE-502]. The EasyMeals theme passes attacker-controlled input into PHP's unserialize() function without validating the source or structure of the serialized data. Calling unserialize() on untrusted input causes the PHP interpreter to instantiate arbitrary classes and invoke magic methods such as __wakeup(), __destruct(), or __toString().

When a class with a dangerous magic method is reachable in the running application, attackers can chain object properties to perform unintended actions. WordPress environments often expose such gadget chains through core classes, theme components, or third-party plugins, which broadens the practical impact of the flaw.

The attack vector is network-based and requires no authentication or user interaction. High attack complexity reflects the need for a usable gadget chain in the target installation.

Root Cause

The root cause is the use of PHP deserialization on input that crosses a trust boundary. The theme does not validate, sign, or restrict the serialized data it consumes. Any endpoint that forwards request parameters into unserialize() becomes a sink for attacker-controlled object graphs.

Attack Vector

An unauthenticated attacker sends an HTTP request to a vulnerable EasyMeals endpoint containing a serialized PHP object payload. The theme deserializes the payload, instantiating objects whose magic methods execute during construction or destruction. With the right gadget chain, the attacker achieves file write, file read, or arbitrary command execution under the web server account.

No proof-of-concept exploit is currently published, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the Patchstack Vulnerability Report for additional technical context.

Detection Methods for CVE-2026-40753

Indicators of Compromise

HTTP request parameters containing serialized PHP object markers such as O: (object), a: (array), or s: (string) followed by class names
Unexpected PHP files, web shells, or scheduled tasks created under the WordPress wp-content/ directory after suspicious requests
Outbound connections from the web server to unfamiliar hosts shortly after requests targeting EasyMeals theme endpoints
New or modified administrator accounts in the WordPress wp_users table without corresponding audit trails

Detection Strategies

Inspect web server and PHP error logs for unserialize() warnings, class-not-found errors, or unexpected magic method invocations
Apply Web Application Firewall (WAF) rules to flag request bodies and query strings containing PHP serialization grammar
Compare installed theme versions across WordPress sites and alert on EasyMeals <= 1.5.1
Baseline file integrity of theme and plugin directories to detect unauthorized writes

Monitoring Recommendations

Forward Apache, Nginx, and PHP-FPM logs to a centralized analytics platform for correlation against deserialization signatures
Monitor outbound network traffic from web servers for command-and-control beaconing
Track WordPress administrative actions, including user creation, role changes, and plugin installs

How to Mitigate CVE-2026-40753

Immediate Actions Required

Identify all WordPress installations running the EasyMeals theme at version 1.5.1 or earlier
Disable the EasyMeals theme on affected sites until a fixed version is installed
Place a virtual patch at the WAF that blocks request parameters containing PHP serialized object syntax targeting theme endpoints
Audit the web server file system for unauthorized files modified after the suspected exposure window

Patch Information

No vendor patch is referenced in the current advisory data. Site operators should monitor the Patchstack Vulnerability Report for an updated theme release and apply it as soon as it becomes available. Until a fixed version ships, the safest action is to remove or replace the EasyMeals theme.

Workarounds

Switch to an alternative WordPress theme until the EasyMeals maintainers publish a patched release
Restrict access to vulnerable theme endpoints using server-side allowlists or authentication gates
Deploy WAF rules that reject HTTP parameters matching PHP serialization patterns such as O:[0-9]+:"
Run the WordPress process under a least-privileged account to limit the impact of any successful exploitation

bash

# Example ModSecurity rule to block PHP serialized objects in requests
SecRule ARGS|ARGS_NAMES|REQUEST_BODY "@rx O:[0-9]+:\"[a-zA-Z_\\\\]+\":[0-9]+:" \
    "id:1040753,phase:2,deny,status:403,log,\
    msg:'CVE-2026-40753 - PHP Object Injection attempt against EasyMeals theme'"