CVE-2026-103646
The Ultimate Multisite WordPress plugin before 2.17.0 does not require authentication before a…
- Risk score
- 71/100
- CVSS
- 9.8 v3.1
- Exploit chance (30 days)
- 0.4%
- Published
- 8 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 c…
- Affected
- See advisory
- Fix
- Upgrade the product to 2.17.0 or later.
- Exploitation
- No known exploitation
Why it is Amber
- CVSS 9.8 critical
- Remotely exploitable without logging in
References
Original 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.
Last activity 8 Oct 2026. Patch Forecast updates every hour.