CVE-2026-81655

Deferred Deferred - Pending Action

Unauthenticated PHP Code Execution in Ad Inserter WordPress Plugin

Publication date: 2026-09-27

Last updated on: 2026-09-28

Assigner: WPScan

Description

The Ad Inserter WordPress plugin before 2.8.19 does not correctly restrict access to one of its settings pages, making it reachable by every logged in user under a configuration its own settings allow, and does not filter the content saved there, allowing users with a role as low as subscriber to store code which is then executed as PHP or served unescaped to site visitors.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-27

Last Modified

2026-09-28

Generated

2026-10-17

AI Q&A

2026-09-27

EPSS Evaluated

2026-10-16

NVD

CVE-2026-81655

EUVD

EUVD-2026-87886

Affected Vendors & Products

Vendor	Product	Version / Range
wpinsert	ad_inserter	From 2.8.12 (inc) to 2.8.19 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-94	The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

Attack-Flow Graph

Executive Summary

This vulnerability affects the Ad Inserter WordPress plugin versions 2.8.12 through 2.8.18. It allows authenticated users with a role as low as subscriber to execute remote code or stored cross-site scripting attacks. The issue occurs because the plugin fails to properly restrict access to a settings page, allowing any logged-in user to save unfiltered code. The saved code is then executed as PHP or served unescaped to visitors.

Detection Guidance

Check the installed version of the Ad Inserter plugin. If it is between 2.8.12 and 2.8.18, the system is vulnerable. Log in as a subscriber or higher and attempt to access the vulnerable settings page to confirm exposure.

Impact Analysis

An attacker with subscriber-level access could inject malicious code into your WordPress site. This could lead to remote code execution, allowing them to take control of your site, steal data, or deface it. Visitors to your site could also be exposed to cross-site scripting attacks, potentially compromising their devices or accounts.

Compliance Impact

This vulnerability could lead to unauthorized access and data breaches, violating GDPR and HIPAA requirements for data protection and security. If exploited, it may result in unauthorized data exposure, leading to legal penalties, fines, or reputational damage for organizations handling sensitive user data.

Mitigation Strategies

Update the Ad Inserter plugin to version 2.8.19 or later immediately. If updating is not possible, consider disabling the plugin until an update is applied. Review user roles and restrict unnecessary access to plugin settings.

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