CVE-2026-89427: Ad Inserter <= 2.8.18 - Reflected Cross-Site Scripting via 's' Search Parameter

Vulnerability summary

CVE-2026-89427 is a medium (CVSS 6.1) Cross-site Scripting vulnerability in spacetime ad inserter – ad manager & adsense ads. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.9% of scored vulnerabilities. Fixed in 2.8.19.

Timeline

1. 01-10-2026
   PublishedVulnerability first disclosed.
2. 03-10-2026
   Last modifiedVulnerability information updated.

Description

The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via 's' Search Parameter in all versions up to, and including, 2.8.18 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Exploitation requires that a site administrator has configured at least one Ad Inserter block using the {title} or {short-title} placeholder with that block enabled for search pages, which is a standard, documented plugin feature.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.