CVE-2026-103646 | BDVDB-2026-384659 Detail
Ultimate Multisite
Description#
The Ultimate Multisite WordPress plugin before 2.17.0 does not require authentication before a logged-out checkout is linked to, and logged in as, an existing WordPress account matching the submitted email address, and its duplicate-account check normalizes that address differently from the lookup used to create the customer, so an unauthenticated attacker can log in as any existing user, including a Network Super Admin, whose email address they know. This bypass is not addressed by the 2.15.1 fix for CVE-2026-75957 and remains exploitable in all versions up to and including 2.16.1, the releases that fix was expected to cover. Exploitation requires a checkout form configured without a password field (auto-generated password) and a target account that has no existing customer record in the Ultimate Multisite WordPress plugin before 2.17.0.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact high. Attack vector: network.
Weaknesses#
- CWE-287 Improper Authentication
References#
Exploit#
History#
- Version 1Record published in the CVE List.