Administrator takeover via premature WP_Error coercion
Published Aug 15, 2026 · Updated Aug 15, 2026
Authentication bypass in Cozmoslabs Profile Builder 3.16.4 and earlier allows remote attackers to gain WordPress administrator access. The wppb_log_in_user() function passes a WP_Error from wp_insert_user() through absint() before checking for an error, turning a rejected 61–70-character username into user ID 1 and issuing that account an autologin nonce. Exploitation requires a reachable front-end registration form, the Automatically Log In after Registration setting, and no prior account; redeeming the nonce authenticates the attacker as user ID 1, ordinarily the administrator.
Summary
What happened
Authentication bypass in Cozmoslabs Profile Builder 3.16.4 and earlier allows remote attackers to gain WordPress administrator access. The wppb_log_in_user() function passes a WP_Error from wp_insert_user() through absint() before checking for an error, turning a rejected 61–70-character username into user ID 1 and issuing that account an autologin nonce. Exploitation requires a reachable front-end registration form, the Automatically Log In after Registration setting, and no prior account; redeeming the nonce authenticates the attacker as user ID 1, ordinarily the administrator.
The record
- CVE
- CVE-2026-15826
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- Cozmoslabs
- Product
- Profile Builder
- Classifications
- CWE-704, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=3.16.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Reported exploitation
- SK-CERT report of active exploitationreported exploitation
Technologies
Your stack
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Your stack
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