CVE-2026-5718
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe 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).
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe plugin fails to properly validate file uploads when custom blacklist types are configured, as it replaces the default dangerous extension denylist instead of merging with it. Additionally, the wpcf7_antiscript_file_name() sanitization function can be bypassed using filenames with non-ASCII characters, allowing unauthenticated attackers to upload arbitrary files like PHP and achieve remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the pluginCheck if the Contact Form 7 plugin is installed and active in the WordPress plugins directoryAffected if The Contact Form 7 plugin is installed and active
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Determine the installed versionView the plugin file header (typically in readme.txt or the main plugin PHP file) to find the version numberAffected if The installed version is older than the patched version (check the plugin repository for the latest version)
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Verify file upload capability is in useSearch form configurations for fields using 'file' type or upload-related settings in the CF7 plugin settingsAffected if Any contact form is configured to accept file uploads
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Check for custom denylist configurationInspect the plugin settings or wp-config.php for custom denylist/blacklist settings related to file uploads (look for patterns like 'wpcf7_file_type_denylist' or similar custom configurations)Affected if Custom denylist configurations are present that may replace rather than merge with the default list
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Inspect uploaded files directoryExamine the WordPress uploads folder (typically wp-content/uploads) for files with dangerous extensions like .php, .php5, .phtml, or files with double extensionsAffected if Unexpected executable files are found in the uploads directory, especially if uploaded by unauthenticated sources
If Contact Form 7 is active with file upload capability and custom denylist settings are configured, the environment is likely affected by this vulnerability.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpdate to the latest version of the plugin immediately. If no full patch is available, consider disabling the plugin or implementing additional file upload restrictions at the web server level (e.g., web server configuration to block PHP uploads to the upload directory).
Latest version available on WordPress Plugin Repository (check for version greater than 1.3.9.7)
- 1. Log in to the WordPress admin dashboard
- 2. Navigate to Plugins > Installed Plugins
- 3. Locate 'Drag and Drop Multiple File Upload for Contact Form 7'
- 4. Check the current installed version number
- 5. If the installed version is 1.3.9.7 or earlier, click 'Update Now' if an update is available
- 6. If no update is available through WordPress, manually download the latest version from the WordPress Plugin Repository at plugins.trac.wordpress.org
- 7. Deactivate the current plugin version
- 8. Delete the current plugin files
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,752.
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Free · runs locallyCheck whether your project pulls in CVE-2026-5718 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-5718 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data