CVE-2026-16035 in 2FA Plugin
Summary
by MITRE • 08/04/2026
The miniOrange 2FA WordPress plugin before 6.2.7 does not restrict who can trigger its second-factor configuration OTP send, nor bind the OTP recipient to the enrolling user's own address, allowing a low-privileged user to send one-time-passcode emails to arbitrary recipients and to exhaust the site's metered OTP allowance, preventing legitimate users from receiving their second-factor codes.
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Analysis
by VulDB Data Team • 08/04/2026
The vulnerability in the miniOrange 2FA WordPress plugin affects versions prior to 6.2.7 and represents a critical authorization flaw that undermines the security of two-factor authentication mechanisms. This issue stems from insufficient access controls during the OTP (One-Time Password) sending process, where the plugin fails to validate whether the user attempting to trigger an OTP is authorized to do so for the specified recipient. The weakness allows any authenticated user within the WordPress system to initiate OTP delivery to arbitrary email addresses without proper verification of ownership or authorization.
From a technical perspective, the flaw manifests as a lack of proper input validation and user binding mechanisms during the second-factor configuration workflow. When a user requests an OTP, the system should verify that the request originates from the legitimate account holder who owns the target email address. However, in affected versions, this verification process is completely bypassed, enabling unauthorized actors to abuse the OTP delivery mechanism for malicious purposes. The vulnerability operates at the application layer and can be exploited through standard web interface interactions without requiring elevated privileges beyond basic user authentication.
The operational impact of this vulnerability extends beyond simple privilege escalation, creating a vector for both denial-of-service attacks and potential credential harvesting. Low-privileged attackers can systematically send OTPs to multiple email addresses, exhausting the site's allocated OTP quota and preventing legitimate users from receiving their authenticator codes when they attempt to configure or use two-factor authentication. This creates a scenario where genuine users become locked out of their accounts due to resource exhaustion, while attackers can potentially identify valid user email addresses through systematic OTP sending attempts.
Security implications align with CWE-285, which addresses insufficient authorization in authentication mechanisms, and can be mapped to ATT&CK technique T1566 for credential harvesting through social engineering or automated attacks. The vulnerability essentially allows attackers to perform unauthorized actions against the OTP delivery system while maintaining their low privilege status within the WordPress environment. Organizations running affected versions face significant risk of account compromise and service disruption, particularly in environments where two-factor authentication is enabled but not properly monitored.
Mitigation strategies should prioritize immediate patching to version 6.2.7 or later, which implements proper access controls and user binding for OTP delivery. Administrators should also implement monitoring of OTP sending activities to detect unusual patterns that may indicate abuse attempts. Additional protective measures include rate limiting on OTP requests, implementing multi-factor authentication for administrative functions, and conducting regular security audits of WordPress plugins to ensure proper authorization controls are in place. Network-level restrictions and logging of authentication-related activities can provide additional layers of defense against exploitation of this vulnerability.