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

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-06-20 · updated 2026-06-17
Weakness: CWE-79

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.

Affected products

mgibbs189 Custom Field Suite: through 2.6.7

References

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

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