What’s Vulnerable › Vulnerabilities

CVE-2026-25863: Conditional Fields for Contact Form 7 < 2.7.3 DoS via Uncontrolled Resource Consumption

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-04 · updated 2026-10-26
• Weakness: CWE-1284

Description

Conditional Fields for Contact Form 7 WordPress plugin through version 2.7.2 contains an uncontrolled resource consumption vulnerability in the Wpcf7cfMailParser class where the hide_hidden_mail_fields_regex_callback() method reads an iteration count directly from user-supplied POST parameters without validation or upper bound enforcement. Unauthenticated attackers can supply an arbitrarily large integer value through the REST API endpoint to cause unbounded loop execution with multiple preg_replace() operations, exhausting server memory and crashing the PHP process.

Affected products

• Jules Colle Conditional Fields for Contact Form 7: before 2.7.3 — fixed in 2.7.3

How to fix

Upgrade to a fixed version: Jules Colle Conditional Fields for Contact Form 7 2.7.3. Check the vendor advisory for mitigations.

References

• https://wordpress.org/plugins/cf7-conditional-fields/#developers
• https://www.vulncheck.com/advisories/conditional-fields-for-contact-form-7-dos-via-uncontrolled-resource-consumption

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