CVE-2026-9626
MediumCVSS 6.4Summary
The JSON API User plugin for WordPress up to version 4.1.0 is vulnerable to Stored Cross-Site Scripting via the 'content' parameter of the post_comment API endpoint. The post_comment() function lacks proper input sanitization, allowing authenticated attackers with subscriber-level access or higher to inject arbitrary web scripts.
Risk Assessment
An attacker can inject malicious scripts that execute in the browser of any user visiting the affected page, potentially leading to session hijacking, redirects, or other harmful actions.
Recommendation
Immediately update the JSON API User plugin to the latest available version that fixes this vulnerability, and consider restricting user privileges to the minimum necessary.
Original NVD description (English source)
The JSON API User plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'content' parameter of the post_comment API endpoint in versions up to, and including, 4.1.0 This is due to insufficient input sanitization in the post_comment() function, which passes the attacker-controlled comment_content value directly to wp_insert_comment() without applying any HTML sanitization, and additionally allows the caller to set comment_approved=1 to self-approve the comment and bypass moderation. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.