---
id: "CVE-2026-126537"
page: "https://infrastack.ai/live/CVE-2026-126537"
kind: "vulnerability"
aliases: ["CVE-2026-126537"]
title: "Ninja Forms File Uploads WordPress add-on: unauthenticated arbitrary file deletion and read"
severity: "critical"
cvss: 9.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ninja-forms", "package", "self-hosted", "wordpress"]
not_affected_if: ["add-on-not-installed", "no-public-file-upload-forms"]
published_at: "2026-11-11T13:17:23+00:00"
first_seen_at: "2026-11-11T13:27:15+00:00"
updated_at: "2026-11-11T13:29:08+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126537", "first_seen_at": "2026-11-11T13:27:15+00:00"}]
exploit_sources: []
---

# Ninja Forms File Uploads WordPress add-on: unauthenticated arbitrary file deletion and read

Link for people: https://infrastack.ai/live/CVE-2026-126537 (this .md is for agents)

The Ninja Forms File Uploads add-on for WordPress lets anonymous visitors submit a file path that the server later deletes or reads, bypassing its own upload-directory check. Deleting wp-config.php can force WordPress into its setup screen, enabling full site takeover.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed version of the Ninja Forms - File Uploads add-on in the WordPress plugins screen or `wp plugin list` against the fixed version.
- Confirm whether the add-on's upload features (S3, Dropbox or Google Drive) are enabled on public forms.

## Fix

- Ninja Forms - File Uploads add-on: move to a version later than `3.3.36` (fixed version not stated in the sources).

## Timeline

- 2026-11-11T13:27:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126537

## From the sources

The Ninja Forms - File Uploads add-on for WordPress is vulnerable to Arbitrary File Deletion (and arbitrary file read via S3/Dropbox/Google Drive exfiltration) in versions up to, and including, 3.3.36. The flaw spans NF_FU_Fields_Upload::process() in includes/fields/upload.php — which returns early (leaving the client-supplied files[] intact) whenever a public submission carries a nonempty extra.saveProgress — and NF_FU_External_Abstracts_Service::process_upload() in includes/external/abstracts/service.php, whose authoritative-path reload only fires when the client sends upload_id. By omitting upload_id, an attacker's data[file_path] survives into the Background Upload queue and is used by both upload_file_to_s3() (as SourceFile) and the maybe_delete_server_file() unlink() call in includes/external/abstracts/backgroundupload.php, with no canonicalization or upload-directory containment check (the plugin's own is_path_within_upload_dir() helper is only applied on admin paths). This makes it possible for unauthenticated attackers to delete arbitrary files on the affected site's server which may make remote code execution possible — specifically, deleting wp-config.php forces WordPress into its setup screen, enabling full site takeover.

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