CVE-2026-2354
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 Swiss Toolkit For WP plugin for WordPress is vulnerable to arbitrary file upload due to a flawed file type validation bypass in the `upload_extension_files()` function in all versions up to, and including, 1.4.6. The `upload_extension_files()` function hooks into WordPress's `wp_check_filetype_and_ext` filter and uses `strpos()` to check if a filename contains a configured extension string, rather than verifying the actual file extension. This makes it possible for authenticated attackers, with Author-level access and above, to upload arbitrary files (including PHP) on the affected site's server which may make remote code execution possible, granted the "Enhanced Multi-Format Image Support" feature is enabled with at least one extension (e.g., avif) in the allowed formats.
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 · moderate confidenceThe Swiss Toolkit For WP plugin has a flawed file extension validation in the upload_extension_files() function. It uses strpos() to check if a filename string contains an allowed extension (like 'avif'), rather than validating the actual file extension. This allows attackers to bypass validation by embedding allowed extensions in filenames like 'malicious.php.avif', enabling authenticated Author+ users to upload arbitrary PHP files and achieve RCE when the Enhanced Multi-Format Image Support feature is enabled.
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
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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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Verify Swiss Toolkit For WP plugin is installedCheck the WordPress plugins directory for the Swiss Toolkit For WP plugin files, typically in /wp-content/plugins/swiss-toolkit-for-wp/ or via WP Admin > PluginsAffected if The plugin is not installed
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Confirm the plugin versionCheck the plugin header in main plugin file (usually swiss-toolkit-for-wp.php) for the Version field, or look at the plugin version listed in WP Admin > PluginsAffected if The installed version is lower than the patched version (compare against latest version on WordPress plugin repository)
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Check if Enhanced Multi-Format Image Support is enabledNavigate to WordPress Admin > Swiss Toolkit settings, or inspect the plugin options in wp_options table for the setting controlling Enhanced Multi-Format Image Support featureAffected if Enhanced Multi-Format Image Support feature is enabled in the plugin settings
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Verify file upload functionality is accessible to Author+ usersCheck WordPress user roles and capabilities. Author role and above typically have upload_files capability. Confirm the upload_extension_files() function is callable by these rolesAffected if Users with Author role or higher can access the file upload functionality through the plugin
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Inspect upload_extension_files() function for strpos() validation flawExamine the plugin source code, specifically the upload_extension_files() function. Look for strpos() being used to validate file extensions rather than proper extension extraction and validationAffected if The code uses strpos($filename, $extension) instead of proper file extension validation, allowing bypasses like 'malicious.php.avif'
A user is affected if Swiss Toolkit For WP is installed with the Enhanced Multi-Format Image Support feature enabled, the plugin has not been updated to the patched version, and Author+ role users can access the upload functionality.
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 Swiss Toolkit For WP when available, or disable the 'Enhanced Multi-Format Image Support' feature if not required. Review uploaded files and consider file type restrictions at the server level.
Latest version newer than 1.4.6 (check WordPress plugin repository for available updates)
- Check the current version of the Swiss Toolkit For WP plugin installed on your WordPress site
- Navigate to Plugins > Installed Plugins in the WordPress admin dashboard
- Locate Swiss Toolkit For WP and note the current version
- Visit the official WordPress plugin repository or the plugin vendor's website to check for the latest version
- If a version newer than 1.4.6 is available, update the plugin to that version
- Verify the update was successful and test that file upload functionality works as expected
- If no update is available, consider disabling the 'Enhanced Multi-Format Image Support' feature as a temporary mitigation until a patch is released
- Audit user accounts and ensure only trusted users with Author-level access or higher exist
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-2354 — 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-2026-2354 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