CVE-2026-2471 in WP Mail Logging Plugin
Summary
by MITRE • 02/28/2026
The WP Mail Logging plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.15.0 via deserialization of untrusted input from the email log message field. This is due to the `BaseModel` class constructor calling `maybe_unserialize()` on all properties retrieved from the database without validation. This makes it possible for unauthenticated attackers to inject a PHP Object by submitting a double-serialized payload through any public-facing form that sends email (e.g., Contact Form 7). When the email is logged and subsequently viewed by an administrator, the malicious payload is deserialized into an arbitrary PHP object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.
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Analysis
by VulDB Data Team • 03/03/2026
The vulnerability identified as CVE-2026-2471 affects the WP Mail Logging plugin for WordPress, representing a critical security flaw that has persisted across all versions up to and including 1.15.0. This vulnerability stems from improper handling of user-supplied data during the deserialization process, creating a pathway for attackers to execute arbitrary PHP code on affected systems. The issue specifically resides within the `BaseModel` class constructor which invokes `maybe_unserialize()` on all database-retrieved properties without implementing proper validation mechanisms. This fundamental design flaw allows malicious actors to craft payloads that exploit the plugin's data handling routines, transforming what should be a simple logging function into a potential attack vector for remote code execution.
The technical exploitation of this vulnerability occurs through a carefully crafted double-serialized payload that targets the email log message field, which is typically populated through public-facing forms such as Contact Form 7 or similar contact mechanisms. When an unauthenticated attacker submits such a payload through these forms, the malicious data gets stored in the database and subsequently retrieved during the logging process. The vulnerability becomes active when an administrator views the email log entries, as this action triggers the deserialization of the malicious payload through the vulnerable `BaseModel` constructor. This deserialization process transforms the serialized object data back into executable PHP objects, effectively executing the attacker's code within the context of the WordPress application. The vulnerability's classification as a PHP Object Injection aligns with CWE-502, which specifically addresses the deserialization of untrusted data, making it particularly dangerous due to its potential for arbitrary code execution.
The operational impact of this vulnerability extends beyond simple data compromise, as it can enable attackers to perform a wide range of malicious activities depending on the server configuration and available POP chains within the target environment. While the vulnerability itself does not contain a built-in POP (Point of Purchase) chain, its exploitation becomes significantly more dangerous when combined with other vulnerable plugins or themes that contain such chains. This dependency on additional vulnerabilities creates a complex attack scenario where the initial exploitation of CVE-2026-2471 serves as a launching point for more sophisticated attacks. The potential actions available to an attacker include deleting arbitrary files, extracting sensitive data, and executing code on the target system, with the exact capabilities depending on the specific POP chain present in the compromised environment. The vulnerability's impact is further amplified by its accessibility through public-facing forms, which are typically designed to be accessible to unauthenticated users, making the attack surface particularly broad.
Mitigation strategies for CVE-2026-2471 should focus on immediate patching of the WP Mail Logging plugin to versions that address the deserialization vulnerability, as well as implementing additional security measures to prevent exploitation. Organizations should prioritize updating to the latest plugin version that resolves this vulnerability, as this represents the most direct and effective solution to prevent exploitation. In addition to patching, administrators should implement input validation and sanitization measures to prevent malicious data from being processed through the logging system. The implementation of proper access controls and monitoring for unusual activity in email logging functions can help detect potential exploitation attempts. Security professionals should also consider implementing network-level protections such as web application firewalls that can detect and block known malicious payloads targeting this specific vulnerability. From an ATT&CK framework perspective, this vulnerability maps to techniques involving server-side request forgery and code injection, with potential lateral movement opportunities if POP chains are present in the environment. Regular security audits and vulnerability assessments should include checking for the presence of vulnerable plugins and themes that may contain exploitable POP chains, as these represent the primary enablers for the full exploitation potential of this vulnerability.