External risk intelligence

Qwery Theme PHP Object Injection Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-78533

The vulnerability exists in a WordPress theme (Qwery). WordPress themes are deployed as components of public-facing web applications, making the associated attack surface commonly reachable via the internet as part of the standard web server interface.

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 Qwery theme, a component often used in public-facing websites. This issue, classified as unauthenticated PHP Object Injection, means an attacker could potentially exploit it without needing any credentials. The primary concern at this time is to confirm whether Qwery is in use and, if so, to understand the potential exposure.

  • Code injection without user login.
  • Affects public-facing websites.
  • Confirm usage and potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending a specially crafted request over the network to a website using the affected software. This could allow them to inject and execute malicious PHP code, potentially leading to full system compromise.

  • No authentication required.
  • Involves injecting malicious PHP objects.
  • Allows arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

An unauthenticated PHP Object Injection vulnerability in Qwery could allow an attacker to inject malicious code or commands. This could occur when the application deserializes untrusted user input, potentially leading to the execution of arbitrary code on the server. The impact depends on the application's configuration and the specific objects that can be unserialized.

  • Server-side code execution.
  • Remote unauthenticated injection.
  • Compromise of application integrity.

Operational Fix

Recommended remediation, mitigation, and detection steps

This unauthenticated PHP Object Injection vulnerability in Qwery could allow an attacker to remotely execute code. Action owners should first identify all Qwery installations, confirm their internet reachability and business criticality, and then assign an accountable owner for remediation planning.

  • Assign Qwery ownership to platform/app teams.
  • Verify Qwery deployment reachability and criticality.
  • Plan remediation based on risk and vendor input.

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 the Qwery theme?

Qwery is a multipurpose WordPress theme used to build and design the visual layout and functionality of websites. Themes like Qwery operate as essential components that run on top of the WordPress core, directly interacting with user requests and server-side processes to display web content.

What does PHP Object Injection mean in CVE-2026-78533?

This vulnerability, classified as CWE-502, occurs when the software incorrectly handles serialized data. An attacker sends a manipulated PHP object that the application trusts and reconstructs. This process can trick the system into executing unintended commands or accessing data it should not, bypassing standard security controls.

How can an attacker trigger this vulnerability?

An attacker triggers this flaw by sending a specially crafted, malicious request over the network to the server hosting the Qwery theme. Because the vulnerability is unauthenticated, no user account or login is required to initiate the attack. Simply browsing to or interacting with a properly configured site is not enough to trigger it; the request must specifically contain the malicious serialized payload.

Is my website at risk from this CVE?

Halo Surface Signal indicates that because Qwery is a WordPress theme designed for public-facing sites, it is typically reachable via the internet. If your installation of Qwery is version 3.6.1 or older, the component is likely exposed. You should prioritize checking any public-facing web servers that utilize this theme for their front-end appearance.

What steps should I take if I use Qwery?

First, create an inventory of all websites running the Qwery theme to determine which are internet-facing. Once identified, confirm the specific version currently in use. Coordinate with your web development or platform team to review vendor guidance and schedule an update or patch, as this is necessary to secure the application against remote code execution attempts.

References