External risk intelligence

Unauthenticated PHP Object Injection in wpForo Forum

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-49769

A critical PHP object injection vulnerability exists in a WordPress forum plugin that can be reached over the network. Unauthenticated attackers may exploit this to inject malicious code, potentially impacting system confidentiality, integrity, and availability. Confirming the plugin's presence and exposure is crucial

5Halo Surface Signal

Deserialization

External exposure likelihood

Halo Surface Signal score for CVE-2026-49769

This vulnerability exists in a WordPress forum plugin. Forum plugins are designed to be public-facing web components that allow user interaction, making them reachable via the public internet by default in any standard deployment.

PCI scan relevance

PCI Relevance for CVE-2026-49769

Yes

CVE-2026-49769 — Halo PCI Relevance: Yes. Under typical PCI ASV external scan criteria, this issue may be flagged for scan prioritization.

This vulnerability is a PHP Object Injection that could lead to an automatic PCI ASV scan failure due to its exploitable nature in unauthenticated scenarios.

Scan-prioritization guidance only—not a PCI DSS certification or ASV attestation.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in a widely used forum plugin for WordPress. This flaw allows unauthenticated attackers to inject malicious code, potentially leading to significant compromise of the affected website's data and operations. The main concern at this time is to confirm if this specific plugin is in use and, if so, to what extent it is exposed.

  • Unauthenticated code injection in forum software.
  • Important for protecting website integrity and data.
  • Confirm relevance and exposure for affected systems.

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 affected forum plugin. This could happen without any prior authentication or interaction from the user. The vulnerability lies in how the plugin handles certain data, allowing an attacker to inject malicious code.

  • No authentication required to start.
  • Triggered by specially crafted network data.
  • Risks include high impact on confidentiality, integrity, and availability.

Live Threat

Current exploitation, exposure, and threat context

A critical PHP Object Injection vulnerability in wpForo Forum, when present in systems accessible via the network, could allow an unauthenticated attacker to execute arbitrary code. This may impact the confidentiality, integrity, and availability of the affected system.

  • System data could be compromised.
  • Remote code execution may occur.
  • Complete system takeover is possible.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

The critical unauthenticated PHP object injection vulnerability in wpForo Forum impacts unpatched versions, requiring immediate attention from teams managing the WordPress ecosystem. The first practical step is to identify all instances of the affected plugin, confirm their exposure and criticality, and then coordinate remediation efforts with the appropriate application or platform owners.

  • WordPress application owners should own the issue.
  • Verify plugin presence and network exposure first.
  • Plan remediation based on risk and maintenance windows.

Frequently asked questions

What is the wpForo Forum plugin?

wpForo Forum is a feature-rich community software component for WordPress websites. It provides the core functionality for discussion boards, user profiles, and member engagement, effectively transforming a standard WordPress site into a collaborative forum platform.

What does CVE-2026-49769 mean?

This CVE describes a weakness known as PHP Object Injection (CWE-502). It occurs when software takes untrusted data and uses it to create an object without proper validation. In this case, it allows an attacker to manipulate the plugin's internal logic to execute unauthorized actions on the server.

How is this vulnerability triggered?

An attacker triggers this flaw by sending specially crafted network requests directly to the forum plugin. It does not require the attacker to have an account, nor does it require a legitimate user to click a link or perform any action. The code execution happens automatically when the plugin processes the malicious data.

Is my website at risk from this vulnerability?

According to Halo Surface Signal, this plugin is designed for public interaction, making it inherently internet-facing in most deployments. If your site uses an affected version of wpForo Forum, it is likely reachable by anyone on the internet, increasing the urgency of verifying your current software version.

Do I need to take action if I use this plugin?

Yes. First, perform an inventory to confirm if you are running version 3.1.0 or earlier of the plugin. Once identified, work with your site administrators to coordinate a security update. Prioritize isolating the forum component if an immediate patch is not available to maintain the integrity of your broader web environment.

References

Sources and related resources

Primary sources: NVD, CVE.org.

NVDPublished