External risk intelligence

777 Triple Seven Theme Object Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-57738

The vulnerability affects a WordPress theme, which is a component of a web application. WordPress themes are commonly used to build public-facing websites and web applications, making the attack surface frequently accessible from 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 critical vulnerability has been identified in the 777 triple-seven WordPress theme, enabling the injection of malicious code through untrusted data. This issue could allow unauthorized access and manipulation of affected systems, impacting data integrity and availability. The primary concern at this stage is to determine if this specific theme version is in use within our environment.

Allows code injection via untrusted data.
Affects public-facing websites and web applications.
Confirm relevance and 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 the affected WordPress theme. This data would target a weakness in how the theme handles deserialization, allowing the attacker to inject malicious objects. Successful exploitation could lead to unauthorized actions and compromise of the application.

Accessible via the network.
Triggered by deserializing untrusted data.
Enables object injection and full system compromise.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated attacker to inject arbitrary PHP objects into the application. When supported by the advisory, this could lead to the execution of malicious code on the server, potentially impacting the integrity and availability of the system.

Affects system integrity and availability.
Via network by deserializing untrusted data.
Potential for remote code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

The real-world ownership of this deserialization vulnerability in the 777 triple-seven WordPress theme likely falls to the application or website owner, supported by the platform team managing the WordPress instance. The initial practical move is to identify all instances of this theme, determine their business criticality and network exposure, and then confirm the accountable owner for remediation planning.

Website owners should prioritize this.
Verify theme usage and reachability.
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 777 triple-seven WordPress theme?

The 777 triple-seven theme by axiomthemes is a design framework used to build and manage the appearance and layout of WordPress-based websites. It acts as a set of templates and scripts that render content for visitors. Because it runs directly on the web server, it must process incoming data correctly to maintain the security of the underlying application environment.

What does Object Injection mean for CVE-2026-57738?

This vulnerability involves the class CWE-502, Deserialization of Untrusted Data. In plain terms, the theme incorrectly trusts information provided by a user or external source when converting it back into a data object. An attacker can supply a specially crafted, malicious object that the application then inadvertently executes, potentially granting unauthorized control over the system's behavior or data.

How is this vulnerability triggered?

The flaw is triggered when the theme processes serialized data sent over the network. If the data is not properly validated before deserialization, the system blindly accepts the malicious object provided by the attacker. This bug does not require any specific user interaction or authentication; however, it is specifically tied to the processing of this untrusted input, not general web traffic that does not involve serialized data structures.

Is my website at risk from this vulnerability?

Halo Surface Signal indicates this is a significant concern because WordPress themes are typically used to build public-facing websites. If your instance is reachable via the internet, it is part of an external attack surface. You should care if you are running version 1.13.0 or older of the 777 theme, as these configurations are vulnerable to network-based inputs.

What should I do if I use this WordPress theme?

Your first step is to inventory your WordPress installations to confirm if 777 triple-seven is active. Once identified, evaluate the criticality of the site and its exposure to the network. Determine who owns the management of the theme and coordinate with them to prioritize updates or protective measures, ensuring you have a clear plan to address the software version before an incident occurs.

References

patchstack.com/database/Wordpress/Theme/triple-seven/vulnerability/w…

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.