CVE-2026-25315 in hCaptcha for WP Plugin
Summary
by MITRE • 02/19/2026
Improperly implemented security check vulnerability in KAGG hCaptcha for WP allows CAPTCHA Functionality Bypass.This issue affects hCaptcha for WP: from n/a through 4.21.1.
The vulnerability is limited to the CAPTCHA mechanism intended to protect a publicly accessible form from automated abuse. It does not impact WordPress-level authentication or authorization controls.
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Analysis
by VulDB Data Team • 03/30/2026
The vulnerability identified as CVE-2026-25315 represents a critical flaw in the KAGG hCaptcha for WP plugin, specifically within its security validation implementation. This issue manifests as an improperly implemented security check that undermines the fundamental purpose of CAPTCHA functionality. The flaw exists within the plugin's handling of CAPTCHA verification processes, creating a potential bypass mechanism that allows automated attacks to circumvent the intended protection measures. The vulnerability affects versions ranging from the initial release through 4.21.1, indicating a prolonged period during which the security gap remained unaddressed. The security check implementation fails to properly validate CAPTCHA responses, potentially allowing malicious actors to submit forms without completing the required human verification process.
The technical nature of this vulnerability places it squarely within CWE-604, which addresses the use of insecure or improperly implemented security checks. The flaw specifically targets the CAPTCHA functionality that is designed to distinguish between human users and automated bots, thereby compromising the plugin's primary defense mechanism. Attackers exploiting this vulnerability can bypass the CAPTCHA verification process, potentially enabling spam submissions, brute force attacks, or other automated abuse of publicly accessible forms. The impact is limited to the form protection aspect of the plugin, meaning that while WordPress authentication and authorization controls remain unaffected, the public-facing form submission mechanisms become vulnerable to automated exploitation. This creates a scenario where malicious actors can flood forms with automated submissions, potentially leading to service disruption or data integrity issues.
The operational impact of this vulnerability extends beyond simple form abuse, as it represents a breakdown in the plugin's security architecture designed to protect against automated attacks. Organizations relying on the hCaptcha for WP plugin for form protection may experience increased spam submissions, potential denial of service conditions, and compromised data quality. The vulnerability's scope suggests that it affects all publicly accessible forms protected by the plugin, making it particularly concerning for websites with contact forms, comment systems, or any user submission interfaces. This bypass capability allows attackers to exploit the form submission mechanisms without proper verification, potentially leading to resource exhaustion or malicious data injection attacks. The issue demonstrates a failure in the principle of least privilege and proper validation, where the system fails to adequately verify user intent before accepting submissions.
Mitigation strategies for CVE-2026-25315 should prioritize immediate plugin updates to versions that address the security check implementation flaw. Administrators should conduct thorough security audits of all forms protected by the plugin to identify potential exploitation attempts. The vulnerability's nature suggests that implementing additional validation layers beyond the CAPTCHA mechanism could provide defense-in-depth. Organizations should consider monitoring form submission patterns for unusual activity that might indicate exploitation attempts. The security controls should be enhanced to include rate limiting and additional verification mechanisms that do not rely solely on CAPTCHA functionality. According to ATT&CK framework concept T1213, which covers data from information repositories, this vulnerability creates an opportunity for attackers to access and potentially abuse form data repositories. Regular security assessments and monitoring of plugin behavior should be implemented to detect similar implementation flaws in other security controls. The remediation process should include verification that all affected forms properly implement CAPTCHA validation and that no bypass mechanisms exist in the system's security architecture.