# CVE-2026-126537: Path traversal in Ninja Forms - File Uploads

> Unauthenticated attackers can delete arbitrary server files, such as wp-config.php, enabling WordPress site takeover; sites using Ninja Forms File Uploads should care.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Harmful if only installed:** No
- **Needs a specific call:** No
- **Fix available:** No
- **Published:** 11 Nov 2026
- **Updated:** 12 Nov 2026
- **Also known as:** GHSA-rfc5-f6j6-9jgj

## What is CVE-2026-126537?

CVE-2026-126537 is a critical path traversal vulnerability in SaturdayDrive Ninja Forms - File Uploads, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-126537?

An affected version is exposed as installed. No special setting or call is needed.


## How do I fix CVE-2026-126537?

No fix has been published for CVE-2026-126537 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-126537 being exploited?

There is no known exploitation of CVE-2026-126537 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-126537 — Ninja Forms File Uploads <= 3.3.36: unauthenticated arbitrary file deletion/read via files[].data.file_path + extra.saveProgress. PoC, analysis, docker lab. (github_poc): https://github.com/im0xfay/CVE-2026-126537

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-126537 and fix it if it is affected.

What it is: CVE-2026-126537 is a critical path traversal vulnerability in SaturdayDrive Ninja Forms - File Uploads, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-126537 in the wild and no public exploit code.
Exposure: An affected version is exposed as installed. No special setting or call is needed.

Affected product: SaturdayDrive Ninja Forms - File Uploads. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-126537/ (Markdown: https://insights.sbomify.com/CVE-2026-126537/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-126537
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126537
- OSV: https://osv.dev/vulnerability/CVE-2026-126537

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-126537/
Summaries are generated and may contain mistakes; the official description above is the record.