CVE-2026-16778 Cross-site scripting in Live Composer – Free WordPress Website Builder
Authenticated contributors can inject arbitrary scripts via shortcode content, leading to stored XSS execution for other users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-16778?
CVE-2026-16778 is a medium-severity cross-site scripting vulnerability in livecomposer Live Composer – Free WordPress Website Builder, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The Live Composer – Free WordPress Website Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'dslc_module_downloads_output' 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 wp_kses_post 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 view_all_link (href attribute), main_heading_title (h2 body), button_text (anchor body), and button_inline_svg (anchor body) — without any escaping at render time.
Weakness: CWE-79
Which versions are affected by CVE-2026-16778?
How do I fix CVE-2026-16778?
No fix has been published for CVE-2026-16778 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-16778 being exploited?
There is no known exploitation of CVE-2026-16778 in the wild and no public exploit code.
Sources
Also known as GHSA-hv57-w5f4-r2xr.