CVE-2026-3335
Received Received - Intake
Missing Authorization in Canto WordPress Plugin Allows Arbitrary File Upload

Publication date: 2026-03-21

Last updated on: 2026-03-21

Assigner: Wordfence

Description
The Canto plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 3.1.1 via the `/wp-content/plugins/canto/includes/lib/copy-media.php` file. This is due to the file being directly accessible without any authentication, authorization, or nonce checks, and the `fbc_flight_domain` and `fbc_app_api` URL components being accepted as user-supplied POST parameters rather than read from admin-configured options. Since the attacker controls both the destination server and the `fbc_app_token` value, the entire fetch-and-upload chain is attacker-controlled — the server never contacts Canto's legitimate API, and the uploaded file originates entirely from the attacker's infrastructure. This makes it possible for unauthenticated attackers to upload arbitrary files (constrained to WordPress-allowed MIME types) to the WordPress uploads directory. Additional endpoints (`detail.php`, `download.php`, `get.php`, `tree.php`) are also directly accessible without authentication and make requests using a user-supplied `app_api` parameter combined with an admin-configured subdomain.
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Meta Information
Published
2026-03-21
Last Modified
2026-03-21
Generated
2026-06-16
AI Q&A
2026-03-21
EPSS Evaluated
2026-06-15
NVD
CVE-2026-3335
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
canto canto to 3.1.1 (inc)
canto canto 2.0.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
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Executive Summary

The Canto plugin for WordPress has a vulnerability called Missing Authorization in all versions up to and including 3.1.1. This occurs because certain files, such as copy-media.php, are directly accessible without any authentication, authorization, or nonce checks.

Attackers can supply POST parameters that should normally be controlled by the admin, allowing them to control the destination server and token values. This means attackers can upload arbitrary files (limited to WordPress-allowed MIME types) to the WordPress uploads directory without being authenticated.

Additional plugin endpoints are also accessible without authentication and use user-supplied parameters combined with admin-configured settings, further increasing the risk.

Impact Analysis

This vulnerability allows unauthenticated attackers to upload arbitrary files to the WordPress uploads directory, which can lead to unauthorized content being hosted on your site.

Since the attacker controls the entire fetch-and-upload process, they can potentially upload malicious files that could be used for further attacks, such as defacement, phishing, or malware distribution.

The lack of authentication and authorization checks means your site’s integrity and security could be compromised without any user interaction.

Compliance Impact

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Detection Guidance

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Mitigation Strategies

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