Vulnerability · Published Mar 31, 2026 · Assigned by Wordfence

CVE-2026-4267Query Monitor <= 3.20.3 - Reflected Cross-Site Scripting via Request URI

High 7.2

In plain English

A high-severity cross-site scripting in Query Monitor from johnbillion. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.2High

Exploit odds (30 days)0.3%top 76.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The Query Monitor – The developer tools panel for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘$_SERVER['REQUEST_URI']’ parameter in all versions up to, and including, 3.20.3 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	johnbillion/query-monitor	3.20.4	GHSA-2xr4-chcf-vmvf

Affected products (as reported)

Vendor	Product	Versions
johnbillion	Query Monitor	0 – through 3.20.3

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

In plain English

Official description

Affected packages & fixed versions

Affected products (as reported)

References