CVE-2026-25863: CWE-1284 Improper Validation of Specified Quantity in Input in Jules Colle Conditional Fields for Contact Form 7
Conditional Fields for Contact Form 7 WordPress plugin through version 2.6.7 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.
AI Analysis
Technical Summary
CVE-2026-25863 is a vulnerability in the Conditional Fields for Contact Form 7 WordPress plugin (up to version 2.6.7) involving improper validation of a user-supplied iteration count in the Wpcf7cfMailParser class. The hide_hidden_mail_fields_regex_callback() method uses this unvalidated input to control loop iterations in preg_replace() calls, resulting in uncontrolled resource consumption. This allows unauthenticated remote attackers to cause a denial of service by exhausting server memory and crashing the PHP process via the REST API endpoint.
Potential Impact
Successful exploitation leads to denial of service by exhausting server memory and crashing the PHP process hosting the WordPress site. This can disrupt website availability and potentially affect other services running on the same server.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting access to the vulnerable REST API endpoint or implementing web application firewall rules to detect and block unusually large iteration count values in POST requests targeting this plugin.
CVE-2026-25863: CWE-1284 Improper Validation of Specified Quantity in Input in Jules Colle Conditional Fields for Contact Form 7
Description
Conditional Fields for Contact Form 7 WordPress plugin through version 2.6.7 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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-25863 is a vulnerability in the Conditional Fields for Contact Form 7 WordPress plugin (up to version 2.6.7) involving improper validation of a user-supplied iteration count in the Wpcf7cfMailParser class. The hide_hidden_mail_fields_regex_callback() method uses this unvalidated input to control loop iterations in preg_replace() calls, resulting in uncontrolled resource consumption. This allows unauthenticated remote attackers to cause a denial of service by exhausting server memory and crashing the PHP process via the REST API endpoint.
Potential Impact
Successful exploitation leads to denial of service by exhausting server memory and crashing the PHP process hosting the WordPress site. This can disrupt website availability and potentially affect other services running on the same server.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting access to the vulnerable REST API endpoint or implementing web application firewall rules to detect and block unusually large iteration count values in POST requests targeting this plugin.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-02-06T19:12:03.463Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69f8eaaecbff5d8610415ae1
Added to database: 5/4/2026, 6:51:26 PM
Last enriched: 5/4/2026, 7:06:50 PM
Last updated: 5/5/2026, 5:55:06 AM
Views: 6
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