Description

The Ninja Forms WordPress plugin from 3.14.10 before 3.15.2 does not prevent shortcodes in request-derived values from being executed when it substitutes them into content it later processes for shortcodes, allowing unauthenticated users to run any shortcode registered on the site.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.8",
  "pubDate": "2026-09-06T10:17:14.693Z",
  "pubdate": "2026-09-06T10:17:14.693Z",
  "executiveSummary": "The Ninja Forms WordPress plugin contains a critical security vulnerability involving the improper handling of user-supplied data, specifically concerning shortcode expansion.\nThe vulnerability is classified as an Improper Neutralization of Input During Web Page Generation, allowing unauthenticated attackers to trigger arbitrary shortcodes within the WordPress environment.\nBy injecting malicious shortcodes into request-derived values, an attacker can influence the plugin's content substitution process, leading to the execution of any shortcode currently registered on the target WordPress installation.\nThe impact of this vulnerability is significant, as it enables unauthorized actors to perform actions or extract data that would otherwise be restricted, depending on the capabilities of the shortcodes available on the site.\nThe flaw affects Ninja Forms versions 3.14.10 through 3.15.1.\nThis vulnerability poses a high risk to organizational security, as it grants unauthenticated users the ability to manipulate application functionality via shortcode injection, potentially leading to unauthorized data disclosure, administrative actions, or server-side exploitation if specific high-privilege shortcodes are present.",
  "technicalDetails": "The root cause of this vulnerability lies in the insecure handling of user-supplied data that is subsequently processed by the WordPress shortcode parsing engine.\nThe Ninja Forms plugin fails to sufficiently sanitize or neutralize request-derived inputs before injecting them into content buffers that are later passed through the do_shortcode() function or a similar recursive shortcode evaluation mechanism.\nIn the affected versions (3.14.10 through 3.15.1), the plugin logic performs a substitution process where data retrieved from HTTP requests—which should be treated as untrusted data—is directly placed into context where WordPress interprets brackets [] as indicators of shortcode execution.\nThe attack flow begins when an unauthenticated attacker identifies a plugin parameter that is echoed back or processed within content rendering. By crafting a request containing a specific shortcode payload—for instance, '[shortcode_name]'—the attacker forces the plugin to treat this input as a legitimate registered shortcode rather than literal string data.\nWhen the WordPress core rendering process executes, the do_shortcode() functionality encounters the attacker-supplied shortcode within the plugin's output. Since the shortcode is registered on the server, the system executes the associated function regardless of the user's current session or authentication status.\nThis behavior bypasses standard application-layer security controls because the payload is not executed via the intended administrative interface, but is instead triggered by the internal processing routine of the plugin.\nThe post-exploitation impact is contingent upon the set of shortcodes installed on the target environment. If other installed plugins or themes register shortcodes that perform sensitive operations—such as modifying post content, exposing database information, or bypassing authentication checks—the attacker can leverage this injection vulnerability to execute those functions remotely.\nThe vulnerability is strictly a result of the failure to isolate user input from the content evaluation phase, transforming a simple data-processing routine into a vehicle for arbitrary execution of WordPress registered hooks.\nBecause the execution happens server-side during the page construction, the resulting output may be delivered directly to the attacker’s browser, facilitating data exfiltration through shortcodes that might otherwise return confidential content."
}