# Wordpress Alert: Stored cross-site scripting in block attributes

A custom block saves a value that later executes in the editor or public page. Editors or visitors can be affected each time the block renders.

2026-08-03
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Switchboard Tech Services


![Wordpress Alert: Stored cross-site scripting in block attributes](https://switchboardtechservices.com/static/images/defaults/guides.webp)

## What it looks like

A custom block saves a value that later executes in the editor or public page.

## Why it matters

Editors or visitors can be affected each time the block renders.

## What to check

Inspect custom block rendering and sanitize allowed HTML before output.

## Documentation

This is an exploit pattern to check in installed components, not a claim that every WordPress site has this flaw. Confirm the product and version against its advisories before treating a site as affected. See [WordPress output escaping](https://developer.wordpress.org/apis/security/escaping/), [WordPress input sanitizing](https://developer.wordpress.org/apis/security/sanitizing/).

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  [WordPress](https://switchboardtechservices.com/guides/categories/wordpress/)
- Tags:
  [#WordPress Security](https://switchboardtechservices.com/guides/tags/wordpress-security/), [#Cross-Site Scripting](https://switchboardtechservices.com/guides/tags/cross-site-scripting/)

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Canonical URL: https://switchboardtechservices.com/guides/wordpress-alert-stored-cross-site-scripting-in-block-attributes/

Language: en-us

Content type: guide

Author: Switchboard Tech Services

Published: 2026-08-03T14:52:31+00:00

Description: A WordPress security alert about stored cross-site scripting in block attributes: signs, impact, and what to check.