What the vulnerability does
01Description
The Async JavaScript plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.19.07.14. This is due to missing authorization checks on the aj_steps AJAX aciton along with a lack on sanitization on the settings saved via the function. This makes it possible for authenticated attackers with subscriber level permissions and above to inject malicious web scripts into a page that execute whenever a user accesses that page.
Explanation of Vulnerability in Simple Terms
02Summary
Async JavaScript versions before 2.20.02.27 contain a cross-site scripting vulnerability that allows an authenticated attacker to inject malicious scripts affecting other users. The vulnerability exists due to insufficient input sanitization in the library. An attacker with low-level privileges can craft payloads that execute in victims' browsers, potentially compromising user sessions or stealing data.
What an attacker can do
03Attacker Capabilities
Inject malicious JavaScript that runs in other users' browsers and affects the site's functionality.
Potential impact on your site
04Site Impact
Authenticated users can inject scripts affecting other users' sessions, data, or site behavior.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege account on the site; no user interaction required from victims.
Key dates
06Disclosure timeline
October 18, 2025
CVE published
April 8, 2026
Record updated
