External risk intelligence

Meta Box AIO Unauthenticated Privilege Escalation Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-39761

The vulnerability affects a WordPress plugin. WordPress plugins are commonly deployed in web-facing applications accessible via the public internet to provide functionality to site visitors, making the attack surface frequently reachable from the outside.

Privilege Escalation

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

This advisory concerns an unauthenticated privilege escalation vulnerability in Meta Box AIO. This type of vulnerability could potentially allow unauthorized users to gain elevated access to systems without needing valid credentials. The main concern at this time is confirming if Meta Box AIO is in use and assessing potential exposure.

  • Unauthenticated users could gain system access.
  • Critical vulnerability allows unauthorized privilege escalation.
  • Confirm relevance and assess potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted requests over the network to a vulnerable system. No authentication is required, and the attacker does not need to interact with the user. This could allow an attacker to gain elevated privileges on the affected system.

  • No authentication required.
  • Network access to trigger.
  • Privilege escalation.

Live Threat

Current exploitation, exposure, and threat context

An unauthenticated privilege escalation vulnerability in Meta Box AIO could allow an attacker to gain elevated access to a WordPress site. This may occur when the plugin is used in a web-facing application, potentially affecting the integrity and availability of the system.

  • Website administrative control.
  • Unauthenticated network access.
  • System compromise and data manipulation.

Operational Fix

Recommended remediation, mitigation, and detection steps

This unauthenticated privilege escalation vulnerability in Meta Box AIO impacts any deployment utilizing the affected plugin. Owners of the websites or applications where this plugin is active are primarily responsible. The immediate first step is to identify all instances of the plugin, assess their reachability and business criticality, and then coordinate with the platform or application owner for remediation, prioritizing the most exposed and critical systems.

  • Application owners.
  • Verify plugin presence and exposure.
  • Plan and execute remediation.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is Meta Box AIO?

Meta Box AIO is a WordPress plugin used by developers to create custom post types, fields, and taxonomies. It simplifies the process of adding complex data structures and metadata to a website without requiring extensive manual coding.

What does CVE-2026-39761 mean?

This CVE describes a flaw classified as Incorrect Privilege Assignment (CWE-266). It means the software does not properly check user identity before granting administrative rights, effectively allowing someone without an account to act with high-level permissions.

How is this vulnerability triggered?

An attacker triggers this by sending a specifically formatted network request to the web server. It does not require the attacker to have an existing account, nor does it require any interaction from legitimate users or administrators to succeed.

Is my site at risk according to Halo Surface Signal?

Halo Surface Signal indicates this vulnerability is likely relevant to your site because Meta Box AIO is a WordPress plugin. Since these plugins are typically part of public-facing web applications, they are often reachable by attackers over the internet.

What should I do first if I use this plugin?

Begin by auditing your environment to confirm where Meta Box AIO is installed. Once you have a complete inventory, evaluate which systems are exposed to the public internet and prioritize those for remediation by coordinating with your application owners.

References