CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HCVE-2026-126537
Ninja Forms - File Uploads <= 3.3.36 - Unauthenticated Arbitrary File Deletion via 'files[].data.file_path' Parameter via 'extra.saveProgress'
Critical (9.1) in saturdaydrive ninja forms - file uploads.
On this page
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.
Severity
- CWE
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory (Path traversal)
- OWASP Top 10
- A01:2025 Broken Access Control
- Published
- Assigned by
- Wordfence (CNA)
- NVD analysis
- Not in the NVD yet
- Record from
- the CVE List, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-126537 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-126537?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-126537?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-126537 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
- saturdaydrive:ninja forms - file uploads
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| SaturdayDrive Ninja Forms - File Uploads | through 3.3.36 |
Attack patterns (CAPEC)
- CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic Likelihood: High · Severity: High
- CAPEC-76 Manipulating Web Input to File System Calls Likelihood: High · Severity: Very High
- CAPEC-78 Using Escaped Slashes in Alternate Encoding Likelihood: High · Severity: High
- CAPEC-79 Using Slashes in Alternate Encoding Likelihood: High · Severity: High
- CAPEC-126 Path Traversal Likelihood: High · Severity: Very High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.