CVE-2026-107431: JetFormBuilder Auth Bypass Vulnerability

CVE-2026-107431 Overview

CVE-2026-107431 is a missing authorization vulnerability in the Crocoblock JetFormBuilder WordPress plugin. The flaw affects all versions up to and including 3.6.6 and stems from incorrectly configured access control security levels [CWE-862]. Unauthenticated attackers can reach protected plugin functionality over the network without user interaction. According to the CVSS vector, exploitation impacts availability of the affected WordPress site. The issue is tracked by Patchstack and published to the National Vulnerability Database (NVD).

Critical Impact
Unauthenticated network attackers can abuse broken access control in JetFormBuilder to disrupt availability of WordPress sites running vulnerable plugin versions.

Affected Products

Crocoblock JetFormBuilder plugin for WordPress
All versions from n/a through 3.6.6
WordPress sites with JetFormBuilder installed and activated

Discovery Timeline

2026-10-14 - CVE-2026-107431 published to NVD
2026-10-14 - Last updated in NVD database

Technical Details for CVE-2026-107431

Vulnerability Analysis

JetFormBuilder exposes plugin endpoints that fail to enforce proper capability or role checks before executing privileged operations. The vulnerability is classified as Missing Authorization under [CWE-862]. Because authorization gates are missing or misconfigured, requests from unauthenticated users reach code paths intended for privileged roles.

The CVSS vector indicates a network-reachable issue requiring no privileges and no user interaction, with impact scoped to availability. An attacker can trigger plugin actions that disrupt normal site operation. Patchstack categorizes the issue as a broken access control vulnerability in versions up to 3.6.6.

Root Cause

The root cause is incorrectly configured access control security levels within JetFormBuilder request handlers. Permission callbacks or capability checks on sensitive actions either return permissive values or are omitted entirely. WordPress plugins must validate current_user_can() and verify nonces on state-changing endpoints; this plugin version does not do so consistently.

Attack Vector

An unauthenticated attacker sends crafted HTTP requests to the vulnerable JetFormBuilder endpoints exposed through admin-ajax.php or REST routes. Because authorization is not enforced, the plugin processes the request and executes the backing action. No verified proof-of-concept has been published. Technical details are available in the Patchstack JetFormBuilder advisory.

Detection Methods for CVE-2026-107431

Indicators of Compromise

Unexpected POST requests from unauthenticated sources to JetFormBuilder AJAX or REST endpoints
Spikes in admin-ajax.php traffic referencing JetFormBuilder actions outside normal user workflows
Site availability degradation or form processing anomalies with no corresponding admin activity

Detection Strategies

Inventory WordPress installations and identify sites running JetFormBuilder at version 3.6.6 or earlier
Review web server access logs for anonymous requests targeting JetFormBuilder endpoints
Correlate WordPress audit logs against web traffic to flag privileged plugin actions without an authenticated session

Monitoring Recommendations

Enable a Web Application Firewall (WAF) with virtual patching rules for JetFormBuilder
Alert on anomalous request volume to /wp-admin/admin-ajax.php and /wp-json/ routes handled by the plugin
Forward WordPress and web server logs to a centralized analytics platform for correlation and retention

How to Mitigate CVE-2026-107431

Immediate Actions Required

Update JetFormBuilder to a version released after 3.6.6 that remediates the broken access control issue
If an update is not immediately possible, deactivate the plugin until a fixed release can be applied
Audit recent form submissions, user accounts, and plugin configuration changes for anomalies

Patch Information

Crocoblock addresses the vulnerability in a release following version 3.6.6. Refer to the Patchstack JetFormBuilder advisory for the exact fixed version and vendor guidance.

Workarounds

Deploy WAF rules that block unauthenticated requests to JetFormBuilder AJAX and REST endpoints
Restrict access to /wp-admin/ and plugin REST routes by IP where operationally feasible
Disable the JetFormBuilder plugin on sites that do not actively require it

bash

# Example WAF-style rule to block unauthenticated access to JetFormBuilder AJAX actions
# (adapt to your WAF or reverse proxy syntax)
SecRule REQUEST_URI "@contains /wp-admin/admin-ajax.php" \
  "chain,deny,status:403,id:1072026,msg:'Block unauth JetFormBuilder action - CVE-2026-107431'"
SecRule ARGS:action "@rx ^jet_form_builder" \
  "chain"
SecRule &REQUEST_COOKIES:/wordpress_logged_in_/ "@eq 0"