CVE-2026-13203 Live Composer <= 2.1.19 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'custom_id' Shortcode Attribute
Authenticated attackers with Contributor access can inject arbitrary scripts via the custom_id shortcode attribute, leading to stored XSS execution on victim pages.
- 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-2026-13203?
CVE-2026-13203 is a medium-severity cross-site scripting vulnerability in livecomposer Live Composer – Free WordPress Website Builder, published on 1 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 the 'custom_id' shortcode attribute of the dslc_modules_section and dslc_modules_area shortcodes in versions up to, and including, 2.1.19. This is due to insufficient input sanitization and output escaping on the user-supplied attribute, which is concatenated into the HTML id="" attribute of the rendered <div> element in the dslc_modules_section_front() and dslc_modules_area_front() functions without esc_attr(). 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-13203?
How do I fix CVE-2026-13203?
No fix has been published for CVE-2026-13203 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-2026-13203 being exploited?
There is no known exploitation of CVE-2026-13203 in the wild and no public exploit code.
Sources
Also known as GHSA-q744-rpmq-q2gw.