Vulnerabilities / Meta Box - WordPress Custom Fields Framework / WPSEC-2026-1299
Meta Box - WordPress Custom Fields Framework <= 5.15.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via Background Field
Medium 6.4
CWE-79Fixed in 5.15.3
- ID
- WPSEC-2026-1299
- Plugin
- Meta Box – A Framework for Dynamic Websites (meta-box)
- Affected
- all versions before 5.15.3
- Remediation
- Update to 5.15.3 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- Weakness
- CWE-79
- Usage
- Plugin Low · Affected versions Low among sites WPSec scans, 2026-10-21
- Attack surface
- Meta Box - WordPress Custom Fields Framework on WPSec AttackSurface
- Fix released
- Published
Description
The Meta Box plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the background field in all versions up to, and including, 5.15.2 due to the sanitizer preserving arbitrary submitted array keys and the formatter concatenating those keys into the output without escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts that execute whenever a user accesses a page where the background field value is rendered. Exploitation requires a background field to be registered on content the attacker can edit.
References
- https://wpsec.com/vuln/WPSEC-2026-1299/
- https://plugins.svn.wordpress.org/meta-box/tags/5.15.3/
- https://wordpress.org/plugins/meta-box/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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