External risk intelligence

Mission Theme Unauthenticated PHP Object Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-62003

The vulnerability affects a WordPress theme, which is a component of a web application. WordPress themes are intended to be internet-facing by design to render content to site visitors. Because this is a web-based component, it is commonly deployed as part of a public-facing website, making it reachable from the internet in standard configurations.

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 Mission theme, potentially impacting web applications. This issue, related to PHP Object Injection, could allow for unauthorized actions within affected systems if exploited. The primary concern is to confirm if this theme is in use within our environment and, if so, to understand the scope of exposure.

Unauthenticated code injection risk in theme.
Critical severity, impacts web applications.
Confirm use; understand potential exposure.

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 web application using the Mission theme. Because no authentication is required, an attacker could trigger the PHP Object Injection flaw, potentially leading to the execution of arbitrary code on the server.

No authentication needed.
Triggered via network requests.
Risk of arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

Unauthenticated PHP Object Injection in Mission could allow attackers to execute arbitrary code. This could occur when the application processes untrusted serialized data, potentially leading to system compromise.

Theme files could be compromised.
Unserialized data could be injected.
Arbitrary code execution may occur.

Operational Fix

Recommended remediation, mitigation, and detection steps

Unauthenticated PHP Object Injection in Mission, a WordPress theme, presents a critical risk requiring immediate attention from the platform or web application owner. The first step is to locate all instances of the affected theme, determine their exposure and business criticality, and then assign ownership for remediation.

Platform or application owners should lead remediation.
Verify theme installations and public exposure.
Plan and execute remediation during maintenance.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is the Mission theme?

Mission is a WordPress theme designed to control the visual presentation and layout of a website. Themes like this act as a foundational layer for WordPress sites, handling how content is rendered and displayed to visitors. Since it functions within the WordPress ecosystem, it is installed on the web server to process requests and deliver web pages to users.

How does CVE-2026-62003 represent a vulnerability?

This CVE involves a weakness known as PHP Object Injection (CWE-502). It occurs when the theme insecurely processes serialized data, which is information formatted for storage or transmission. By injecting malicious objects, an attacker can manipulate the application's logic, potentially leading to unauthorized code execution on the server.

Do I need to be logged in for this to be triggered?

No, authentication is not required to trigger this vulnerability. The flaw is exploitable by sending specially crafted data directly over the network to the affected web application. Simply viewing or interacting with a standard page does not trigger it; an attacker must intentionally submit malicious serialized data that the theme will process.

Why should I care if my site is internet-facing?

Halo Surface Signal identifies this as a high-risk scenario because the Mission theme is inherently designed to be public-facing to serve content. Since the vulnerability is reachable over the network, any instance of the theme exposed to the internet provides a potential pathway for an attacker to reach the underlying server without needing prior access.

Is there a first step for managing this threat?

Start by auditing your environment to locate all active installations of the Mission theme. Verify which web applications are using versions 1.22 or older. Once you have identified the locations and assessed their business importance, coordinate with your team to plan for updates or maintenance to remove or replace the vulnerable component.

References

patchstack.com/database/wordpress/theme/mission/vulnerability/wordpr…

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.