Vulnerability in Ad Inserter – Ad Manager & AdSense Ads — CVE-2026-19902

MediumSeverity
CVSS 6.1

—Estimated exploit probability
EPSS

300,000+ sitesInstalls

2.8.19Fixed in

What to do now

Update Ad Inserter – Ad Manager & AdSense Ads to 2.8.19 or later.

Affected versions

Everything up to and including 2.8.18

Affected: Ad Inserter – Ad Manager & AdSense Ads (plugin, ad-inserter)

Check: The plugin on wordpress.org / Our record for Ad Inserter – Ad Manager & AdSense Ads

The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the Referer header in all versions up to, and including, 2.8.18 due to insufficient input sanitization and output escaping on the '{search-query}' dynamic tag. When an ad block's code contains that tag, replace_ai_tags() reads $_SERVER['HTTP_REFERER'] and tests it with the regex /[\.\/](google|yahoo|bing|ask)\.[a-z\.]{2,5}[\/]/i. The leading [\.\/] class matches a literal slash, so any referrer merely containing a segment such as '/google.com/' passes as a search-engine referral; the plugin then percent-decodes the referring query with parse_str() and substitutes the resulting 'q' (or 'p') value into the block via preg_replace() with no escaping. This makes it possible for unauthenticated attackers to execute arbitrary JavaScript in the context of the site for any visitor, including a signed-in administrator, by luring them to an attacker-controlled page that frames or links to any ordinary post. Exploitation requires the site to have an ad block whose code uses the '{search-query}' tag with automatic insertion enabled — a documented plugin feature used as intended.

This description is reproduced verbatim from the public vulnerability record.

This page is compiled automatically from public databases. Accuracy is not guaranteed; confirm against the vendor advisory before acting.

Vulnerability in Ad Inserter – Ad Manager & AdSense Ads — CVE-2026-19902

What to do now

What the vulnerability is

Sources