CVE-2026-16778
Live Composer <= 2.1.21 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'dslc_module_downloads_output' Shortcode Content
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.
INFO
Published Date :
Sept. 22, 2026, 8:16 a.m.
Last Modified :
Sept. 22, 2026, 8:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-16778
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Live Composer plugin immediately.
- Remove or sanitize user-generated content.
- Implement strict input validation.
- Ensure output escaping is applied.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-16778.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-16778 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-16778
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-16778 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-16778 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Sep. 22, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/16xxx/CVE-2026-16778.json">CVE-2026-16778</a> Added Reference https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/modules/downloads/module.php#L4978 Added Reference https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/modules/downloads/module.php#L5219 Added Reference https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/modules/downloads/module.php#L5225 Added Reference https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/modules/downloads/module.php#L5502 Added Reference https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/modules/downloads/module.php#L5508 Added Reference https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/modules/downloads/module.php#L5685 Added Reference https://plugins.trac.wordpress.org/changeset?reponame=&old=3705127%40live-composer-page-builder&new=3705127%40live-composer-page-builder Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/1d072660-515c-4fd9-903b-815447786e03?source=cve