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.
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Fixes

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History

Fri, 28 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
Description 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.
Title WPMU DEV Dashboard <= 5.0.1 - Authentication Bypass to Administrator via SSO HMAC Canonicalization Confusion
Weaknesses CWE-347
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-08-28T06:39:49.567Z

Reserved: 2026-08-19T14:05:51.938Z

Link: CVE-2026-76581

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-28T08:16:41.463

Modified: 2026-08-28T08:16:41.463

Link: CVE-2026-76581

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses