CVE-2026-14236 Overview
CVE-2026-14236 is an open redirect vulnerability in the Contact Form 7 WordPress plugin versions prior to 2.5. The plugin fails to validate the host of a user-supplied return URL before using it as the success and cancel redirect targets in a Stripe checkout flow. An unauthenticated attacker can craft a malicious link that redirects a victim to an arbitrary external site after the checkout completes. This flaw is categorized under CWE-601 (URL Redirection to Untrusted Site).
Critical Impact
Attackers can leverage the trusted plugin domain to redirect users to phishing pages or malware distribution sites after a legitimate Stripe checkout flow.
Affected Products
- Contact Form 7 WordPress plugin versions before 2.5
- WordPress sites using the plugin's Stripe checkout integration
- Site visitors interacting with checkout links
Discovery Timeline
- 2026-07-27 - CVE-2026-14236 published to NVD
- 2026-07-27 - Last updated in NVD database
Technical Details for CVE-2026-14236
Vulnerability Analysis
The vulnerability resides in the Stripe checkout integration of the Contact Form 7 plugin. When a checkout session is initialized, the plugin accepts a return URL from user-controlled input and passes it directly to Stripe as both the success_url and cancel_url parameters. Because the plugin does not validate the host component of that URL against an allowlist of trusted domains, an attacker can supply any external destination.
The attack requires user interaction, since the victim must click a crafted link and complete or cancel the Stripe checkout flow. Once Stripe processes the session, the victim is redirected to the attacker-controlled URL. This creates a trust-transfer scenario, where the redirect originates from the victim's legitimate interaction with the WordPress site.
Root Cause
The root cause is missing host validation on user-supplied redirect targets. The plugin should compare the host of the return URL against the site's own domain or a defined allowlist before using it in Stripe checkout parameters. Instead, the plugin trusts the input as provided, treating any URL as a valid redirect target.
Attack Vector
Exploitation is performed over the network without authentication. An attacker constructs a URL that triggers the Contact Form 7 Stripe checkout flow with a return URL parameter pointing to an attacker-controlled site. The attacker distributes this link through phishing emails, forum posts, or social media. After the victim completes or cancels the Stripe flow, the browser is redirected to the attacker's destination, which may host credential harvesting pages or drive-by download content.
Refer to the WPScan Vulnerability Report for additional technical details on the parameter handling.
Detection Methods for CVE-2026-14236
Indicators of Compromise
- Web server access logs showing Contact Form 7 Stripe checkout requests with return URL parameters containing external hostnames
- Referrer traffic patterns where users depart the site to unfamiliar third-party domains after checkout events
- Phishing reports from users citing links that pass through the WordPress site before reaching a suspicious page
Detection Strategies
- Inventory WordPress installations and identify Contact Form 7 plugin versions below 2.5
- Inspect HTTP request logs for Stripe checkout initialization endpoints and parse the return URL parameter for off-site hosts
- Correlate outbound redirect events with known phishing infrastructure using threat intelligence feeds
Monitoring Recommendations
- Enable verbose logging on the WordPress site for plugin-initiated Stripe sessions and retain logs for retrospective analysis
- Alert on any redirect target whose host does not match the site's registered domain
- Monitor user reports and abuse mailboxes for phishing complaints referencing the affected site
How to Mitigate CVE-2026-14236
Immediate Actions Required
- Update the Contact Form 7 WordPress plugin to version 2.5 or later on all affected sites
- Audit any custom code or extensions that pass URLs into the Stripe checkout integration
- Review recent access logs for suspicious redirect parameters and notify potentially impacted users
Patch Information
The vendor addressed the flaw in Contact Form 7 version 2.5 by validating the host of the return URL before using it as the Stripe success and cancel redirect targets. Site administrators should apply the update through the WordPress plugin manager or by deploying the fixed release manually. See the WPScan Vulnerability Report for reference.
Workarounds
- Disable the Stripe checkout functionality of the plugin until the patch can be deployed
- Deploy a web application firewall rule that rejects requests to the checkout endpoint when the return URL host differs from the site's domain
- Restrict access to checkout initialization endpoints to authenticated sessions where feasible
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
