CVE-2026-16778: Live Composer <= 2.1.21 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'dslc_module_downloads_output' Shortcode Content
The Live Composer – Free WordPress Website Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'dslcmoduledownloadsoutput' Shortcode Content in all versions up to, and including, 2.1.21 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The save-time wpksespost check is bypassed because the payload is stored as a serialized string containing no HTML tags for kses to tokenize, and the shortcode callback re-emits attacker-controlled values — including viewalllink (href attribute), mainheadingtitle (h2 body), buttontext (anchor body), and buttoninlinesvg (anchor body) — without any escaping at render time.
Affected Software
Event History
Frequently Asked Questions
What level of access does an attacker need?
An attacker must be authenticated with contributor-level access or higher. No user interaction is required from the attacker beyond being able to save the crafted content.
Who is exposed once malicious content has been saved?
Any user who accesses an injected page can have attacker-supplied script execute in their browser. The vulnerability has scope changed and can affect confidentiality and integrity.
Which shortcode values should be reviewed during triage?
Review dslc_module_downloads_output content, particularly the view_all_link, main_heading_title, button_text, and button_inline_svg values. These attacker-controlled values are emitted without output escaping when the shortcode is rendered.
Which plugin versions should be considered affected?
All versions through and including 2.1.21 are affected according to the available information.