Cross-Site Scripting (XSS) in Live Composer – Free WordPress Website Builder (WordPress plugin) (CVE-2026-16778)
Summary
Cross-site scripting in Live Composer – Free WordPress Website Builder (WordPress plugin) (CVE-2026-16778). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-16778 has been found in Live Composer – Free WordPress Website Builder (WordPress plugin).
Risk of unauthorized operations or information disclosure. CVSS score: 6.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Live Composer – Free WordPress Website Builder (WordPress plugin) CVE-2026-16778" on the vendor's site.
CVE-2026-16778 (Live Composer – Free WordPress Website Builder (WordPress plugin)) — CWE-79 / CVSS v3 6.4
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in Live Composer – Free WordPress Website Builder (WordPress plugin).
Check the vendor advisory for the affected versions of Live Composer – Free WordPress Website Builder (WordPress plugin).
Severity: Medium (CVSS 6.4/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Live Composer – Free WordPress Website Builder (WordPress plugin) を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。