cve-2026-76581

CRITICAL CVSS 9.8 vulncheck_kev
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.

Timeline
Published
2026-08-27 00:00 UTC
Last Modified
2026-08-27
CVSS Details

CVSS details not available.

Affected Products

No product information available.

References

No references available.

Linked Vulnerabilities

No linked vulnerabilities found.

{
  "cvss": 9.8,
  "datePublished": "2026-08-27T00:00:00Z",
  "dateUpdated": "2026-08-27T00:00:00Z",
  "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.",
  "dueDate": "",
  "id": "CVE-2026-76581",
  "kev_catalogs": [
    "vulncheck"
  ],
  "knownRansomwareCampaignUse": "Unknown",
  "product": "WPMU DEV Dashboard",
  "requiredAction": "Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.",
  "severity": "CRITICAL",
  "source": "vulncheck_kev",
  "title": "  Improper Verification of Cryptographic Signature",
  "vendor": "wpmudev"
}
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