Vulnerability in Wpmudev Wpmu Dev Dashboard
CVE-2026-76581
The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.0.1. This is due to inconsistent and ambiguous HMAC message construction between the unauthenticated `wdpsso_step1` and `wdpsso_step2` AJAX actions, where step 1 signs and discloses an unseparated concatenation of the token, state, redirect, and domain values, while step 2 verifies an unseparated concatenation that omits the domain field. This makes it possible for unauthenticated attackers, on sites connected to WPMU DEV with Hub SSO enabled and mapped to an administrator, to obtain a valid HMAC from step 1 and replay it to step 2 by moving the domain value into the redirect field, resulting in an authenticated administrator session.
EPSS: 0.003 (26.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-76581?
- CVE-2026-76581 is a critical-severity vulnerability in Wpmudev Wpmu Dev Dashboard, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.8/10. Published 2026-08-28.
- How severe is CVE-2026-76581?
- Critical severity. CVSS v3 base score is 9.8 out of 10.