CVE-2026-2471 is a vulnerability classified under CWE-502 (Deserialization of Untrusted Data) affecting the WP Mail Logging plugin for WordPress, specifically all versions up to and including 1.15.0. The root cause is the BaseModel class constructor invoking the maybe_unserialize() function on all properties retrieved from the database without validating the data's integrity or source. This behavior allows an attacker to submit a double-serialized PHP object payload through any public-facing form that triggers email sending, such as Contact Form 7. When the email is logged by the plugin and later viewed by an administrator, the malicious payload is deserialized into a PHP object. However, the vulnerability alone does not lead to direct exploitation because no gadget or POP (Property Oriented Programming) chain exists within the WP Mail Logging plugin itself to leverage the injected object for malicious actions. The risk materializes only if another plugin or theme installed on the WordPress site contains a suitable POP chain, which could then be exploited to execute arbitrary code, delete files, or access sensitive data. The vulnerability is remotely exploitable without authentication but requires user interaction (administrator viewing the logs). The CVSS v3.1 score is 7.5 (high), reflecting the potential for significant impact on confidentiality, integrity, and availability if combined with a POP chain. No known public exploits or active attacks have been reported at this time. The vulnerability was published on February 28, 2026, and assigned by Wordfence. No official patch links are currently available, indicating that mitigation relies on defensive measures until an update is released.

If exploited in conjunction with a POP chain from other plugins or themes, this vulnerability could lead to severe consequences including remote code execution, arbitrary file deletion, and unauthorized data disclosure. Organizations using WP Mail Logging on WordPress sites face risks to the confidentiality of sensitive email content, integrity of website files, and availability of services due to potential destructive actions. Since the vulnerability is exploitable remotely without authentication, attackers can target publicly accessible WordPress sites with vulnerable plugin versions. The requirement for an administrator to view the malicious email log to trigger deserialization means that social engineering or timing attacks could be used to maximize impact. The absence of a POP chain in the plugin itself limits standalone exploitation, but the widespread use of WordPress and the common practice of running multiple plugins increases the attack surface. This vulnerability could be leveraged in targeted attacks against high-value WordPress sites, especially those with complex plugin ecosystems. The impact is thus significant for organizations relying on WordPress for business-critical functions, particularly those handling sensitive communications.

1. Monitor for and apply security updates from the WP Mail Logging plugin vendor as soon as patches become available to address this vulnerability directly. 2. Restrict access to the WordPress admin dashboard and specifically the email log viewing interface to trusted administrators only, minimizing the risk of triggering deserialization by unauthorized users. 3. Audit all installed plugins and themes for known POP chains or gadget chains that could be exploited in combination with this vulnerability; remove or update any identified risky components. 4. Implement Web Application Firewall (WAF) rules to detect and block suspicious serialized payloads submitted through public-facing forms that send emails. 5. Employ strict input validation and sanitization on all forms that send emails to reduce the risk of injection of malicious serialized data. 6. Consider disabling or limiting the use of WP Mail Logging temporarily if patching is not immediately possible, especially on high-risk or public-facing sites. 7. Educate administrators about the risk of viewing untrusted email logs and encourage caution when inspecting logs from unknown or suspicious sources. 8. Use security plugins that can detect anomalous deserialization attempts or unusual plugin behavior to provide early warning of exploitation attempts.