External risk intelligence

Youzify Plugin Unauthenticated Deserialization Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-73397

Youzify is a WordPress plugin used to add community and social networking features to public-facing websites. As these features are inherently intended to be accessed by web visitors, the plugin code is typically exposed to the public internet as part of the website's front-end surface.

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 Youzify, a plugin that enhances community and social networking features for websites. This issue allows for the deserialization of untrusted data, meaning that improperly handled data could potentially lead to significant security risks. The concern is primarily around confirming whether our systems utilize this specific technology and understanding the scope of exposure.

Untrusted data can be deserialized by the plugin.
It allows unauthorized data handling and could impact systems.
Confirm relevance and exposure of this plugin.

Attack Path

How an attacker could exploit the issue

An unauthenticated attacker could exploit this vulnerability by sending specially crafted data to a vulnerable Youzify installation. This could occur over the network without requiring any prior access or authentication. If successful, the attacker could trigger the deserialization of untrusted data, potentially leading to the compromise of the affected website.

No authentication required.
Deserialization of untrusted data.
Critical remote code execution risk.

Live Threat

Current exploitation, exposure, and threat context

Unauthenticated deserialization of untrusted data could allow an attacker to execute arbitrary code when supported by the advisory. This could impact the integrity and availability of the affected system.

System data and user data at risk.
Exploitation via network requests.
Potential for full system compromise.

Operational Fix

Recommended remediation, mitigation, and detection steps

Real-World Ownership This vulnerability affects the Youzify plugin, commonly used for community and social networking features on public-facing websites. The first practical step is to identify all instances of Youzify across your WordPress deployments, confirm their reachability from the internet, and determine business criticality. The platform or web administration team, in conjunction with the application owner responsible for the website, should coordinate to assign ownership and plan remediation based on the assessed risk.

Website platform and application owners.
Verify internet reachability and business criticality.
Plan remediation based on risk and maintenance windows.

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 Youzify plugin used for?

Youzify is a WordPress plugin designed to add community and social networking features, such as user profiles, activity streams, and social logins, to websites. It is typically installed to encourage visitor interaction and build a public-facing community platform.

What does deserialization of untrusted data mean for CVE-2026-73397?

This vulnerability, classified as CWE-502, occurs when the plugin takes data from a user and converts it back into an object without proper validation. Because the plugin blindly trusts this input, an attacker can manipulate the data structure to force the application to perform unintended actions, such as executing unauthorized code.

How can an attacker trigger this vulnerability?

An attacker triggers this by sending a specially crafted network request containing malicious data to the Youzify plugin. No prior login or account access is required to initiate the attack. However, merely visiting a site using the plugin normally does not trigger the bug; the request must be intentionally malformed to exploit the deserialization process.

Is my website at risk from this vulnerability?

According to Halo Surface Signal, Youzify is designed for community features that are inherently accessible to web visitors. Because these components are typically hosted on the front end of a website and exposed to the public internet, any instance of the vulnerable plugin is considered to have a highly accessible attack surface.

What should I do if I am running Youzify?

First, inventory your WordPress environments to identify all active installations of Youzify. Check your plugin version to see if it is 1.3.7 or older. Once identified, consult your administrative team to prioritize these sites based on their business importance and coordinate a plan to apply available software updates or remove the plugin if a patch is not yet viable.

References

patchstack.com/database/wordpress/plugin/youzify/vulnerability/wordp…

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.