User Profile Builder <= 3.16.4 - Unauthenticated Authentication Bypass via Type Confusion to Administrator Account Takeover via 'username' Parameter
CVSS v3
9.8
CRITICAL
EPSS Score
0.8%
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
The User Profile Builder plugin for WordPress is vulnerable to Authentication Bypass via Type Confusion in versions up to, and including, 3.16.4. This is due to the wppb_log_in_user() function calling absint() on the return value of wp_insert_user() before performing an is_wp_error() check — when a registration is submitted with a 61–70 character username, WordPress core rejects it with a WP_Error object, but absint() coerces that object to the integer 1 before the error check can short-circuit
The User Profile Builder plugin for WordPress is vulnerable to Authentication Bypass via Type Confusion in versions up to, and including, 3.16.4. This is due to the wppb_log_in_user() function calling absint() on the return value of wp_insert_user() before performing an is_wp_error() check — when a registration is submitted with a 61–70 character username, WordPress core rejects it with a WP_Error object, but absint() coerces that object to the integer 1 before the error check can short-circuit
Active exploitation of CVE-2026-15826 has not been confirmed. The EPSS score is 0.8%, indicating the estimated probability of exploitation in the next 30 days.
CVE-2026-15826 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string 3.1.
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Ranked by exploit probability (EPSS).