CVE-2026-1866

High

Published: 10 February 2026

Published

10 February 2026

Modified

15 April 2026

KEV Added

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Patch

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CVSS Score 7.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS Score 0.0019 40.0th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-1866 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 40.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as Machine Learning Libraries; in the Protocol-Specific Risks risk domain.

Threat & Defense at a Glance

What attackers do: exploitation maps to Drive-by Compromise (T1189) and 1 other technique.

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

SI-10 Information Input Validation

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

SI-15 Information Output Filtering

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access

Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.

attack.mitre.org →

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.

attack.mitre.org →

Why these techniques?

Stored XSS in public-facing WP plugin form directly enables Drive-by Compromise via malicious script execution on page load and is itself an instance of exploiting a public-facing application.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

The Name Directory plugin for WordPress is vulnerable to Stored Cross-Site Scripting via double HTML-entity encoding in all versions up to, and including, 1.32.0. This is due to the plugin's sanitization function calling `html_entity_decode()` before `wp_kses()`, and then calling `html_entity_decode()`…

again on output. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page via the 'name_directory_name' and 'name_directory_description' parameters in the public submission form granted they can trick the site administrator into approving their submission or auto-publish is enabled.

Deeper analysisAI

CVE-2026-1866 is a stored cross-site scripting (XSS) vulnerability in the Name Directory plugin for WordPress, affecting all versions up to and including 1.32.0. The flaw stems from the plugin's sanitization function calling `html_entity_decode()` before `wp_kses()`, followed by another `html_entity_decode()` call on output, enabling double HTML-entity encoding bypass. This allows arbitrary web scripts to be injected via the 'name_directory_name' and 'name_directory_description' parameters in the plugin's public submission form. The vulnerability carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N) and is associated with CWE-79 (Cross-site Scripting).

Unauthenticated attackers can exploit this vulnerability by submitting malicious payloads through the public form. The injected scripts will execute whenever a user accesses the affected page, provided the site administrator approves the submission or auto-publishing is enabled, such as by tricking the administrator into approval. Successful exploitation enables attackers to steal sensitive data, perform actions on behalf of authenticated users, or deface pages, with low confidentiality and integrity impacts but changed scope due to client-side execution.

References include code locations in helpers.php (line 604) and shortcode.php (lines 41 and 193) from version 1.31.0, highlighting the double decoding issue, along with WordPress plugin trac changeset 3455023, which appears to address the flaw in the trunk. Wordfence threat intelligence provides further details on the vulnerability (ID: 29d13457-ac60-4e3d-9d8b-0141e6f8f4f6). Security practitioners should update to a patched version beyond 1.32.0 and review submissions in affected plugins.