CVE-2026-0726
Published: 20 January 2026
Summary
CVE-2026-0726 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Wordpress (inferred from references). Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 37.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
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.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-3405
Vulnerability details
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
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.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the PHP object injection vulnerability by requiring timely patching of the affected Nexter Extension plugin to version 4.4.7 or later.
Prevents object injection by enforcing validation of untrusted inputs prior to deserialization in functions like 'nxt_unserialize_replace'.
Mitigates exploitation risk by restricting user installation of additional plugins or themes that could provide POP chains necessary for impactful attacks.