EUVD Vulnerability Catalog
EUVD-2026-96279
Severity: CRITICAL
Base Score: 9.8
CVSS Version: 3.1
Vulnerability Description
The WPCOM Member plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 1.7.27 via the `uuid` and `code` parameters of the social-login callback handler registered on the `init` hook. The vulnerability exists because the `login` function's social-login flow performs no nonce validation, no OAuth state verification, and no per-visitor namespace isolation in the session store, allowing an unauthenticated attacker to issue a crafted GET request that writes an attacker-named, attacker-valued entry into the global session namespace (bypassing the per-visitor prefix by prepending an underscore), then issue a second GET request triggering `weapp_new_user()` to read that forged entry and resolve the attacker-supplied `openid` value to a bound WordPress account before `wp_set_auth_cookie()` establishes a fully authenticated session. This makes it possible for unauthenticated attackers to log in as any WordPress user — including administrators — whose bound social provider identifier (openid/unionid) is known or discoverable. Successful exploitation requires that the target site has at least one social provider configured (which activates the vulnerable handler) and that the attacker knows or can enumerate the victim account's bound openid or unionid.
CVSS Vector Analysis
Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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Attack Vector (AV): Network
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Attack Complexity (AC): Low
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Privileges Required (PR): None
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User Interaction (UI): None
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Scope (S): Unchanged
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Confidentiality Impact (C): High
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Integrity Impact (I): High
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Availability Impact (A): High
Affected Vendors & Systems
Vendor
whyun
References & Advisory Links
- https://www.wordfence.com/threat-intel/vulnerabilities/id/3dee7f76-bd66-4e54-8ef6-bbf581ebcc11?source=cve
- https://plugins.trac.wordpress.org/browser/wpcom-member/tags/1.7.27/includes/social-login.php#L1235
- https://plugins.trac.wordpress.org/browser/wpcom-member/tags/1.7.27/includes/social-login.php#L91
- https://plugins.trac.wordpress.org/browser/wpcom-member/tags/1.7.27/includes/social-login.php#L674
- https://plugins.trac.wordpress.org/browser/wpcom-member/tags/1.7.27/includes/class-sesstion.php#L13
- https://plugins.trac.wordpress.org/browser/wpcom-member/trunk/includes/social-login.php
Metadata Profile
Database Authority
European Union Agency for Cybersecurity (ENISA) EUVD
Assigner
Wordfence
EPSS Probability
0
Known Aliases
GHSA-gj32-ffvm-frj6
CVE-2026-104803
Published On
2026-10-10
Last Updated
2026-10-10