CVE-2026-1400

High

Published: 28 January 2026

Published

28 January 2026

Modified

15 April 2026

KEV Added

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Patch

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CVSS Score v3.1 7.2 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0013 32.5th percentile

Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-1400 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Web Shell (T1505.003); ranked at the 32.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as LLM Application Platforms; in the Supply Chain and Deployment risk domain.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and AC-6 (Least Privilege).

Deeper analysis

CVE-2026-1400 is an arbitrary file upload vulnerability in the AI Engine – The Chatbot and AI Framework for WordPress plugin, affecting all versions up to and including 3.3.2. The flaw arises from missing file type validation in the `rest_helpers_update_media_metadata` function, classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). It carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H) and was published on 2026-01-28.

Authenticated attackers with Editor-level access or higher can exploit the vulnerability by uploading a benign image file and then leveraging the `update_media_metadata` REST endpoint to rename it as a PHP file in the WordPress uploads directory. This allows creation of an executable PHP file on the server, potentially leading to remote code execution.

References to the vulnerable code appear in the plugin's trac browser for version 3.3.0 at lines 1104 and 1141 of classes/rest.php, with a fix applied in changeset 3447500 to the trunk. The Wordfence threat intelligence page provides further details on the issue.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-4890

Vulnerability details

The AI Engine – The Chatbot and AI Framework for WordPress plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the `rest_helpers_update_media_metadata` function in all versions up to, and including, 3.3.2. This makes…

it possible for authenticated attackers, with Editor-level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible. The attacker can upload a benign image file, then use the `update_media_metadata` endpoint to rename it to a PHP file, creating an executable PHP file in the uploads directory.

CWE(s): CWE-434

AI Security AnalysisAI

AI Category: LLM Application Platforms
Risk Domain: Supply Chain and Deployment
OWASP Top 10 for LLMs 2025: None mapped
Classification Reason: Matched keywords: ai

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1505.003 Web Shell Persistence

Adversaries may backdoor web servers with web shells to establish persistent access to systems.

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?

Arbitrary file upload via missing validation directly enables web shell deployment (T1505.003) on a public-facing WordPress application (T1190), resulting in RCE.

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