PatchSiren cyber security CVE debrief
CVE-2026-4267 johnbillion CVE debrief
The Query Monitor plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the '$_SERVER['REQUEST_URI']' parameter in all versions up to, and including, 3.20.3. This is due to insufficient input sanitization and output escaping. An unauthenticated attacker could inject arbitrary web scripts if they can trick a user into performing an action such as clicking on a link.
- Vendor
- johnbillion
- Product
- Query Monitor
- CVSS
- HIGH 7.2
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-03-31
- Original CVE updated
- 2026-07-24
- Advisory published
- 2026-03-31
- Advisory updated
- 2026-07-24
Who should care
Administrators and users of the Query Monitor plugin for WordPress should be aware of this vulnerability and take immediate action to protect their sites. This vulnerability could allow an attacker to inject malicious scripts, potentially leading to unauthorized actions or data breaches.
Technical summary
The Query Monitor plugin for WordPress is vulnerable to Reflected Cross-Site Scripting (XSS) due to insufficient input sanitization and output escaping in the '$_SERVER['REQUEST_URI']' parameter. This vulnerability affects all versions up to and including 3.20.3. An attacker could exploit this by crafting a malicious link that, when clicked by a user, injects arbitrary web scripts into the page. This could lead to unauthorized actions or data manipulation if the user has appropriate privileges.
Defensive priority
High priority should be given to updating the Query Monitor plugin to a version beyond 3.20.3. In the meantime, additional monitoring and security measures should be implemented to detect and prevent exploitation attempts.
Recommended defensive actions
- Update the Query Monitor plugin to the latest version available, which should include a fix for this vulnerability.
- Implement additional security measures such as Web Application Firewalls (WAFs) to detect and prevent common XSS attacks.
- Educate users about the risks of clicking on suspicious links and the importance of keeping software up-to-date.
- Regularly monitor your WordPress site for unusual activity or signs of exploitation.
- Review compensating controls for exposed systems while remediation is scheduled and verified.
- Check relevant monitoring, detection, and logs for exposed assets that need extra review.
- Track exceptions, retest remediated assets, and close the item only after evidence is documented.
Evidence notes
The CVE record was published on 2026-03-31T12:16:31.360Z and was last modified on 2026-07-24T20:10:00.147Z. The vulnerability was reported by [email protected] and has a CVSS score of 7.2, classified as HIGH severity. Multiple references are provided, including links to the WordPress plugin repository and security research sites.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-03-31T12:16:31.360Z and has not been modified since then.