WPCOM Member <= 1.7.27 - Unauthenticated Authentication Bypass via Social-Login Callback
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. This allows 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.
What to do
Update the WPCOM Member plugin to version 1.8.0 or later.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| WordPress plugin | WPCOM Member | <= 1.7.27 | 1.8.0 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-287- Platform
- WordPress
- Package
WPCOM Member- Disclosed
- 09.10.2026
- Updated
- 11.10.2026 15:19
Sources and licenses · Edited or translated by DockRay; source rights and applicable licenses are retained.
Wordfence Intelligence - 3dee7f76-bd66-4e54-8ef6-bbf581ebcc11 - Wordfence Intelligence
Copyright 1999-2026 The MITRE Corporation
Copyright 2012-2026 Defiant Inc.
This record contains material that is subject to copyright
Copyright 1999-2026 The MITRE Corporation
CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
https://www.cve.org/Legal/TermsOfUseCopyright 2012-2026 Defiant Inc.
Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy.
https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/Wordfence Intelligence
Wordfence Intelligence - Defiant, Inc. Copyright Defiant, Inc. All rights reserved except as granted below. License grant, section 3.1 of the Wordfence Intelligence Terms and Conditions (January 26, 2026): Subject to this Agreement, Company hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute the Service. Any copy you make for such purposes is authorized provided that you reproduce Company’s copyright designation, this license, and the license of any disclosed Company licensor in any such copy. Full applicable Agreement: https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/
Vulnerability history: WPCOM Member
All published vulnerabilities of this package (WordPress plugin), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 8
- First → latest
- 09.2024 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 3
- High 4
- Medium 1
Disclosures per year
- 2024: 2
- 2025: 5
- 2026: 1
-
WPCOM Member <= 1.7.27 - Unauthenticated Authentication Bypass via Social-Login Callback this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.