CVE-2026-6127: Elementor Website Builder <= 4.0.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via REST API

Severity: medium (CVSS 6.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-01 · updated 2026-06-17
Weakness: CWE-79

Description

The Elementor Website Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the _elementor_data meta field in versions up to, and including, 4.0.4. This is due to insufficient input sanitization when processing form-encoded REST API requests. The plugin registers the _elementor_data meta field with show_in_rest but omits a sanitize_callback, relying instead on a rest_pre_insert_post filter (sanitize_post_data function) that only sanitizes JSON-encoded request bodies. When a contributor sends a form-encoded PATCH request to the WordPress REST API, the json_decode() call on the raw body returns null, causing all sanitization to be skipped. The unsanitized data is then stored via update_post_meta() and later output without escaping through multiple widget sinks including the HTML widget's print_unescaped_setting() function. 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.

Affected products

Elementor Website Builder: through 4.0.4

References

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