External risk intelligence

Adrena Theme PHP Object Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-65576

The vulnerability exists in a WordPress theme, which is a type of web application component. WordPress sites are frequently deployed as public-facing web services, making the theme's code directly reachable and exploitable from the internet in common deployment patterns.

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 a widely used type of web application component, potentially allowing unauthenticated attackers to inject malicious code. This could impact the confidentiality, integrity, and availability of systems. The primary concern at this time is to confirm if this specific technology is in use within our environment.

Unauthenticated code injection is possible.
Affects a common web application component.
Confirm relevance and exposure.

Attack Path

How an attacker could exploit the issue

An attacker can trigger this vulnerability by sending a specially crafted request to a web server hosting an affected version of Adrena. Because the vulnerability is unauthenticated and exposed to the network, an attacker does not need any prior access or credentials to interact with the vulnerable component. Successful exploitation could allow an attacker to inject arbitrary PHP objects, potentially leading to significant compromise of the application and server.

No authentication required for access.
Triggered via network requests to the application.
Allows arbitrary object injection and code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated attacker to inject malicious PHP objects into the Adrena theme, potentially leading to the execution of arbitrary code or the compromise of system data when supported by the advisory.

System data and sensitive information.
Unauthenticated network injection.
Arbitrary code execution or data compromise.

Operational Fix

Recommended remediation, mitigation, and detection steps

PHP Object Injection in Adrena themes may allow unauthenticated attackers to inject malicious PHP objects, impacting the confidentiality, integrity, and availability of the affected WordPress sites. The first step is to identify all instances of Adrena themes, determine their exposure and business criticality, and assign ownership to the application or platform team responsible for managing WordPress customizations. Subsequent actions will depend on the confirmed risk and available maintenance windows for remediation.

Application owners should own the issue.
Verify theme usage and exposure.
Plan remediation based on 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 Adrena theme?

Adrena is a WordPress theme used to control the visual presentation and layout of websites built on the WordPress platform. Themes like Adrena serve as a layer of code that interacts with the underlying PHP environment to render pages for visitors. Because it functions as a core component of the site's interface, it is loaded and executed whenever a user navigates to the website.

What does PHP Object Injection mean for CVE-2026-65576?

This vulnerability is classified as CWE-502, Deserialization of Untrusted Data. In plain English, the theme incorrectly handles data sent by users, allowing an attacker to inject their own structured PHP objects. This can trick the application into executing unauthorized commands, potentially granting the attacker control over the site's data or the server itself.

How is this vulnerability triggered?

An attacker triggers the flaw by sending a specifically formatted network request to a site running an affected version of Adrena. No valid login or prior interaction is required. It is important to note that simply viewing a page or browsing the site as a regular user does not trigger the bug; the attacker must deliberately send a malicious request designed to exploit the theme's handling of serialized data.

Why is this considered a high-priority risk?

According to Halo Surface Signal, this vulnerability is considered a likely risk because it exists within a WordPress theme. Since WordPress sites are typically deployed as public-facing web services, the Adrena theme's code is often reachable directly from the internet. This accessibility means that any external actor can attempt to interact with the vulnerable component without needing to bypass internal network protections.

Do I need to check my systems for Adrena?

Yes. The first step is to perform an inventory of your WordPress installations to see if the Adrena theme is active, specifically checking for versions 1.2.14 or older. Once you identify which sites are running this theme, coordinate with the responsible platform or application teams to assess the business impact and prepare for necessary updates or configuration changes to remove the risk.

References

patchstack.com/database/wordpress/theme/adrena/vulnerability/wordpre…

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.