External risk intelligence

Hallelujah Theme Object Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-112853

The vulnerability affects a WordPress theme, which is a component of a web application. WordPress sites are frequently deployed as public-facing web services, making the theme's code commonly exposed to the internet.

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 vulnerability in the Hallelujah WordPress theme allows attackers to inject malicious code, potentially leading to unauthorized system access and data compromise. This type of flaw, known as deserialization of untrusted data, is critical because it can be exploited without requiring user interaction or special privileges. The main concern is confirming if our organization utilizes this specific theme and, if so, understanding its exposure.

Malicious code can be injected into our systems.
Affects a public-facing web application component.
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 data to a web application that uses the Hallelujah theme. This data could be processed in a way that allows for object injection, leading to the execution of arbitrary code on the server.

No authentication or special access needed.
Submitting malicious data to the application.
Arbitrary code execution on the server.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated attacker to inject arbitrary PHP objects into a vulnerable WordPress site when supported by the advisory. This could potentially lead to the execution of malicious code or the compromise of system data.

Asset: Website code and data.
Exposure: Via specially crafted requests to the website.
Consequence: Site compromise or data corruption.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in the Hallelujah theme requires the application owner to identify all instances of the theme, confirm their online exposure, and assess business criticality. Coordination with the vendor or plugin management team will be necessary for remediation planning.

Application owners should manage this issue.
Verify theme presence and online exposure first.
Plan remediation based on verified risk.

Supplementary metadata

CVSS vector

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.

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Frequently asked questions

What is the Hallelujah theme?

Hallelujah is a WordPress theme designed by axiomthemes. WordPress themes act as the visual and functional interface for websites, controlling how content is displayed and how users interact with the site's layout. Because themes run on the web server, they can include custom PHP code that processes user requests and handles data interactions.

What does deserialization of untrusted data mean for CVE-2026-112853?

This vulnerability, classified as CWE-502, occurs when the theme processes incoming data without proper validation. Deserialization is a programming process that converts stored data back into active objects. When an application trusts this input blindly, an attacker can inject malicious objects, potentially tricking the server into running unauthorized commands or changing its behavior.

How does an attacker trigger this vulnerability?

An attacker triggers this flaw by sending a specially crafted request containing malicious data to a WordPress site using the affected Hallelujah theme. The vulnerability does not require the attacker to have an account, special permissions, or user interaction. If the site does not process user data through the vulnerable path, the injection cannot occur.

Is my site at risk if it uses Hallelujah?

If you use this theme, your site is likely exposed. According to Halo Surface Signal, this vulnerability affects a WordPress theme, which is a common component of web applications. Because these sites are frequently deployed as public-facing services, the theme's code is often accessible to the internet, increasing the chance an attacker could reach the vulnerable component.

Do I need to take action if I run Hallelujah?

Yes, you should begin by creating an inventory of all websites in your environment to identify which ones use the Hallelujah theme. Once you have located the instances, confirm if they are connected to the internet. After establishing this, coordinate with your web management team to plan for updates or security patches provided by the theme developer.

References

patchstack.com/database/wordpress/theme/hallelujah/vulnerability/wor…

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.