CVE-2026-94256 in SMS Alert Plugin
Summary
by MITRE • 10/10/2026
The SMS Alert WordPress plugin before 4.0.1 does not verify that the account being logged in is the one the verified one-time code belongs to, allowing unauthenticated attackers to sign in as any user with a stored phone number, including an administrator, by completing a code challenge on a phone they control.
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Analysis
by VulDB Data Team • 10/10/2026
The vulnerability identified in SMS Alert WordPress plugin versions prior to 4.0.1 represents a critical authentication bypass flaw rooted in the failure of server-side session validation during the multi-factor authentication process. The core technical deficiency lies in the logic governing one-time password verification, where the system accepts a valid code without binding it strictly to the specific user account or session context that initiated the request. This architectural oversight allows an attacker who possesses control over a phone number registered within the WordPress database to impersonate any associated user identity. By initiating a login sequence and providing the correct SMS-based one-time code received on their device, the attacker can successfully authenticate as the target account without possessing the actual password or other primary credentials.
This flaw effectively neutralizes the security benefits of two-factor authentication for affected users. In a properly secured implementation, the verification token must be cryptographically linked to both the user identity and the specific login session identifier to prevent such substitution attacks. Because SMS Alert fails to enforce this binding mechanism, an attacker can exploit stored phone numbers in the database to gain unauthorized access. The impact is particularly severe when targeting administrative accounts, as it grants full control over the WordPress installation. This includes the ability to modify site configurations, install malicious plugins or themes, exfiltrate sensitive data from the database, and potentially pivot into other systems connected via shared credentials or network trust relationships.
From a classification perspective, this vulnerability aligns with CWE-287, which describes Improper Authentication, specifically highlighting failures in verifying user identity during multi-factor processes. It also maps to MITRE ATT&CK technique T1078, Valid Accounts, as the attacker leverages legitimate credentials stored within the application's infrastructure rather than exploiting a software bug that allows code execution or memory corruption. The attack vector is classified as remote and unauthenticated initially, requiring only knowledge of which phone numbers are associated with high-privilege accounts to execute successfully.
Mitigation strategies must prioritize immediate version updates to SMS Alert 4.0.1 or later, where the developers have addressed this logic error by ensuring strict association between verification codes and user sessions. Until patching is feasible, administrators should consider disabling SMS-based authentication if possible, replacing it with more robust methods such as time-based one-time passwords generated via authenticator applications that are bound to specific devices rather than phone numbers susceptible to SIM swapping or interception. Additionally, implementing account lockout policies after multiple failed attempts and monitoring for unusual login patterns can help detect exploitation attempts in real-time. Regular audits of user accounts should also be conducted to remove unused phone number associations, thereby reducing the attack surface available to potential adversaries seeking to leverage this authentication bypass mechanism.