Path Traversal in Saturdaydrive Ninja Forms - File Uploads

CVE-2026-126537

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

FIRST.org has not scored this CVE yet. About EPSS.

Affected products

Weakness classification (CWE)

Public exploits and proof-of-concept code

1 public repository with exploit or proof-of-concept code for this CVE:

  • im0xfay/CVE-2026-126537 (last pushed 2026-11-12): 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.

References