CVE-2026-81825: Simple Ajax Chat <= 20260811 - Unauthenticated Stored Cross-Site Scripting
The Simple Ajax Chat – Add a Fast, Secure Chat Box plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Chat Message in all versions up to, and including, <= 20260811 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The nonce protecting chat message submission is publicly visible on the chat page, rendering it ineffective as an authentication barrier and allowing fully unauthenticated attackers to submit malicious messages that are stored persistently and rendered to all visitors on every page load.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
Any unauthenticated remote attacker can submit a malicious chat message. The submission nonce is publicly visible on the chat page, so it does not prevent unauthorized message submission.
Which installations are affected?
All versions of the WordPress Simple Ajax Chat plugin up to and including version 20260811 are affected.
When does the malicious code run?
The injected script is stored persistently and executes when users access a page that renders the malicious chat message. The description indicates it can be rendered to visitors on every page load.