WPMU DEV Dashboard <= 5.0.0 - Authentication Bypass to Arbitrary Plugin Installation (Remote Code Execution) via Forged WDP_AUTH HMAC on ?wpmudev-hub= Endpoint
Strategic Overview
- Status
- Patched in 5.0.1
- Affected Plugin
- WPMU DEV Dashboard
- Affected Version
<= 5.0.0- CVSS
- 8.1High
- Weakness type
- CWE-287 · Improper Authentication
- CVE
CVE-2026-15459
At a glance
CVE-2026-15459 is a high-severity Improper Authentication vulnerability in the WPMU DEV Dashboard WordPress plugin, affecting versions <= 5.0.0. It carries a CVSS score of 8.1 (reachable over the network; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 5.0.1; sites on affected versions should update now. Disclosed August 2026, reported by Austin Ginder.
Vulnerability Overview
The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.0.0. On sites not yet connected to the WPMU DEV Hub — the default state after installation — the site API key that keys the WDP-AUTH request signature is empty, making the signature verified by validate_hash() trivially forgeable; version 5.0.0 additionally removed the replay check in validate_nonce(), and the remote handler is bound to the public init hook with no capability check. This makes it possible for unauthenticated attackers to invoke privileged Hub actions — including installing and activating a plugin from an attacker-supplied URL (resulting in remote code execution), deleting plugins and themes, upgrading WordPress core, or logging in as an administrator via SSO. Sites connected to a WPMU DEV account, which have a non-empty 64-character API key, are not affected.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-287: Improper Authentication
WPMU DEV Dashboard <= 5.0.0 carries this weakness at validate_hash(), and reaching it takes a caller who can reach the endpoint. Improper authentication means the mechanism that proves who a caller is can be satisfied without the secret it was supposed to require.
An attacker authenticates as another user — administrators included — without ever knowing a password, so password policies and login rate limits never come into play. For WPMU DEV Dashboard the fix is 5.0.1: builds <= 5.0.0 are affected, anything from 5.0.1 onward is not.
Remediation
Update to version 5.0.1, or a newer patched version
How WordSec helps
Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: WPMU DEV Dashboard 5.0.1 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
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