CVE-2026-3335
Canto <= 3.1.1 - Missing Authorization to Unauthenticated File Upload
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.3
Canto <= 3.1.1 - Missing Authorization to Unauthenticated File Upload
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.
- Record
CVE-2026-3335- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
EUVDEUVD-2026-14013
5.3
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.
- Record
EUVD-2026-14013- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-j9m2-xx67-38fc
5.3
The Canto plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and...
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.
- Record
GHSA-j9m2-xx67-38fc- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
NVD
5.3
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.
- Record
CVE-2026-3335- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | Canto <= 3.1.1 - Missing Authorization to Unauthenticated File Upload |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, Nuclei, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-3335 is a medium vulnerability (CVSS 5.3) in Flightbycanto Canto, published March 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.17%, the 67th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/0777f759-6980-4572-a866-0210bd5f5085?source=cve
plugins.trac.wordpress.org/browser/canto/tags/3.1.1/includes/lib/copy-media.php
plugins.trac.wordpress.org/browser/canto/trunk/includes/lib/copy-media.php
nvd.nist.gov/vuln/detail/CVE-2026-3335
github.com/advisories/GHSA-j9m2-xx67-38fc