---
title: "CVE-2026-104803: WPCOM Member - Authentication Bypass"
description: "WPCOM Member plugin for WordPress <= 1.7.27 contains an authentication bypass caused by missing nonce validation and OAuth state verification in social-login callback, letting unauthenticated attackers log in as any user with known social provider ID, exploit requires configured social provider and knowledge of victim's openid or unionid."
url: https://panop.io/threat-heartbeat/CVE-2026-104803/
---

# CVE-2026-104803 WPCOM Member - Authentication Bypass

WPCOM Member plugin for WordPress <= 1.7.27 contains an authentication bypass caused by missing nonce validation and OAuth state verification in social-login callback, letting unauthenticated attackers log in as any user with known social provider ID, exploit requires configured social provider and knowledge of victim's openid or unionid.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.45% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-104803)

## Details

Type

Authentication Bypass

Impact

Privilege Escalation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

10 October 2026

Updated

15 October 2026

Weakness

[CWE-287](https://cwe.mitre.org/data/definitions/287.html)

## Vendor fix

Update to the latest version beyond 1.7.27.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-104803](https://nvd.nist.gov/vuln/detail/CVE-2026-104803)
- [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#L91)
- [https://plugins.trac.wordpress.org/browser/wpcom-member/trunk/includes/social-login.php](https://plugins.trac.wordpress.org/browser/wpcom-member/trunk/includes/social-login.php)
- [https://www.wordfence.com/threat-intel/vulnerabilities/id/3dee7f76-bd66-4e54-8ef6-bbf581ebcc11?source=cve](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/class-sesstion.php#L13](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/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#L1235)
- [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/social-login.php#L674)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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