External risk intelligence

Participants Database Object Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-112862

The vulnerability affects a WordPress plugin designed to manage databases via a web interface. Such plugins are typically installed on web servers and expose functionality directly to visitors or site administrators through web-based forms and endpoints, making the vulnerable code path commonly reachable over the public internet in standard website deployments.

Deserialization

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in the Participants Database plugin for xnau webdesign, specifically related to the deserialization of untrusted data. This flaw could allow an attacker to inject malicious objects into the system, potentially leading to significant compromises. The main concern is confirming whether our environments utilize this specific plugin and are exposed to this risk.

Untrusted data allows code injection.
Critical flaw in a common web plugin.
Confirm relevance and exposure to this risk.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted data over the network to a website using the Participants Database plugin. This data would trigger the plugin's deserialization process, leading to the injection of malicious objects. If successful, an attacker could potentially gain significant control over the affected system.

No authentication or privileges required.
Triggered by deserializing untrusted data.
Enables object injection and high impact.

Live Threat

Current exploitation, exposure, and threat context

A deserialization of untrusted data vulnerability in the Participants Database plugin could allow for object injection when supported by the advisory. This could potentially impact the integrity and availability of the participant data and the service itself when processed through specific endpoints.

Participant data and service integrity.
Via deserialization of untrusted data.
Potential for unauthorized actions or data loss.

Operational Fix

Recommended remediation, mitigation, and detection steps

This deserialization vulnerability in Participants Database likely requires action from the application owner and potentially the platform or infrastructure teams responsible for the web server. The first practical step is to identify all instances of the Participants Database, assess their reachability and business criticality, and locate the accountable owner before planning remediation.

Application owners should prioritize remediation.
Verify instance reachability and business criticality.
Plan maintenance for targeted updates.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is Participants Database?

Participants Database is a WordPress plugin developed by xnau webdesign. It provides tools for site administrators to create, manage, and display records of individuals, such as contact lists or member directories, directly through a web-based interface.

What does CVE-2026-112862 mean by Object Injection?

This vulnerability, classified as CWE-502, involves the insecure deserialization of untrusted data. When the plugin processes data from an untrusted source, it can be tricked into creating unexpected objects. This weakness allows an attacker to manipulate application logic, potentially leading to unauthorized control over the system.

How is this vulnerability triggered?

An attacker triggers this flaw by sending specially crafted, malicious data over the network to a site running the affected plugin. The vulnerability is exploited when the plugin automatically processes this input during its deserialization routine. Legitimate administrative actions or standard database entries that do not contain malicious, structured object payloads will not trigger this specific vulnerability.

Is my server at risk from this vulnerability?

Halo Surface Signal indicates that because this plugin is designed to expose data-handling forms and endpoints to visitors, it is likely reachable over the public internet. If your WordPress site uses this plugin and is accessible online, it may be exposed to external network traffic capable of triggering the vulnerability.

What should I do if I run Participants Database?

Begin by auditing your environment to locate every instance of the Participants Database plugin. Confirm who is responsible for maintaining each site, assess its business importance, and verify if the plugin is currently active. Once identified, prepare to update the software as soon as a fix is available, ensuring you follow standard maintenance procedures for your WordPress infrastructure.

References

patchstack.com/database/wordpress/plugin/participants-database/vulne…

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.