CVE-2026-39575 WordPress Custom Query Blocks plugin <= 5.5.0 - Cross Site Scripting (XSS) vulnerability
An attacker can execute arbitrary scripts in the victim's browser via DOM-based XSS in the Custom Query Blocks plugin.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-39575?
CVE-2026-39575 is a medium-severity cross-site scripting vulnerability in Ronald Huereca Custom Query Blocks, published on 8 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Ronald Huereca Custom Query Blocks post-type-archive-mapping allows DOM-Based XSS.This issue affects Custom Query Blocks: from n/a through <= 5.5.0.
Weakness: CWE-79
Which versions are affected by CVE-2026-39575?
How do I fix CVE-2026-39575?
No fix has been published for CVE-2026-39575 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-39575 being exploited?
There is no known exploitation of CVE-2026-39575 in the wild and no public exploit code.
Sources
Also known as GHSA-2mw3-cgxq-9prq.