Cyber Posture

CVE-2026-0726

High

Published: 20 January 2026

Published
20 January 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0016 37.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Description

The Nexter Extension – Site Enhancements Toolkit plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 4.4.6 via deserialization of untrusted input in the 'nxt_unserialize_replace' function. This makes it possible for unauthenticated attackers…

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to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates the PHP object injection vulnerability by requiring timely patching of the affected Nexter Extension plugin to version 4.4.7 or later.

prevent

Prevents object injection by enforcing validation of untrusted inputs prior to deserialization in functions like 'nxt_unserialize_replace'.

prevent

Mitigates exploitation risk by restricting user installation of additional plugins or themes that could provide POP chains necessary for impactful attacks.

Security SummaryAI

CVE-2026-0726 is a PHP Object Injection vulnerability (CWE-502) affecting the Nexter Extension – Site Enhancements Toolkit plugin for WordPress in all versions up to and including 4.4.6. The flaw stems from deserialization of untrusted input in the 'nxt_unserialize_replace' function, enabling injection of a PHP Object. It carries a CVSS v3.1 base score of 8.1 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H), reflecting high potential impact despite requiring high attack complexity.

Unauthenticated attackers can exploit this vulnerability remotely by supplying crafted input that triggers the deserialization. On its own, the issue has no practical impact, as no known Property-Oriented Programming (POP) chain exists within the vulnerable plugin. Exploitation becomes dangerous only if another plugin or theme installed on the target WordPress site provides a compatible POP chain, potentially allowing attackers to delete arbitrary files, retrieve sensitive data, or execute arbitrary code based on the specific chain available.

Advisories point to mitigation via updating to Nexter Extension version 4.4.7 or later, where the vulnerable code in nexter-ext-replace-url.php has been patched, as shown in the plugin's Trac changeset diff. Further details on detection and remediation are provided in Wordfence's threat intelligence report.

Details

CWE(s)

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

PHP Object Injection vulnerability in a public-facing WordPress plugin directly enables exploitation of public-facing applications via unauthenticated remote deserialization of untrusted input.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References