XSS in Livecomposer Live Composer – Free WordPress Website Builder

CVE-2026-13203

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-13203: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-13203?
CVE-2026-13203 is a medium-severity vulnerability in Livecomposer Live Composer – Free WordPress Website Builder, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-09-01.
How severe is CVE-2026-13203?
Medium severity. CVSS v3 base score is 6.4 out of 10.