CVE-2026-15826

9.8 CRITICAL 4% exploit odds No fix listed Auth & access Web app

What it is

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 execution, causing the plugin to bind and return a transient-backed autologin nonce tied to user ID 1. This makes it possible for unauthenticated attackers to log in as the site's Administrator account (user ID 1), resulting in full administrative takeover of the site.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 3.9% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2026-07-15 13:58 UTC ReservedThe CVE id was reserved by its CNA
2026-08-15 07:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-08-20 12:48 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 3.9% in the next 30 days (EPSS).
Severity: 9.8 CRITICAL (CVSS).
Fix: none linked yet, which raises it.

Details

Published: 2026-08-15 07:16 UTC
Last modified: 2026-08-20 12:48 UTC
Exploit probability: 3.9% · EPSS, next 30 days
Weakness: CWE-704
Record status: Deferred

Attack profile CVSS 3.1 · 9.8

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-15826.md and follow it. Check whether this project is affected by CVE-2026-15826. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

· More options · Status badge

Download Square Reddit

References

NVD record · CVE.org record