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MEDIUM

Canto <= 3.1.1 - Missing Authorization to Unauthenticated File Upload

Published Mar 21, 2026

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.

Affected products

Remediation

No remediation recorded yet.

References (8)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner Wordfence
Published Mar 21, 2026
Updated Apr 8, 2026
Reserved Feb 27, 2026
CISA Vulnrichment
Updated Mar 23, 2026
NVD
Status Deferred
Modified Jun 17, 2026
Red Hat
Severity n/a
Public date n/a
ENISA EUVD
Assigner Wordfence
Published Mar 21, 2026
Updated Apr 8, 2026
Exploited since n/a
EUVD-2026-14013