CVE-2026-103427

MEDIUM 6.4

Simple Membership <= 4.8.4 - Authenticated (Subscriber+) Stored Cross-Site Scripting via Country Field

CVSS Score

6.4

EPSS Score

0.0%

EPSS Percentile

0th

The Simple Membership plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'country' parameter in all versions up to, and including, 4.8.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Unauthenticated attackers may also exploit this vulnerability when the plugin's Enable Free Membership feature is turned on, as it permits anonymous front-end registration and profile submission.

CWE	CWE-79
Vendor	wpinsider-1
Product	simple membership
Published	Oct 10, 2026

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CVSS v3 Breakdown

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

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

wpinsider-1 / Simple Membership

0 ≤ 4.8.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/fbebb9d4-c445-473d-a5f6-beac00ebe7aa?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/simple-membership/tags/4.8.4/classes/class.swpm-utils-misc.php#L1060 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/simple-membership/tags/4.8.4/views/admin_member_form_common_part.php#L42 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/simple-membership/tags/4.8.4/classes/class.swpm-form.php#L158 downloads.wordpress.org: https://downloads.wordpress.org/plugin/simple-membership.4.8.5.zip

Credits

Maciej Komorowski