Budibase Authentication Bypass (CVE-2026-31816) Detection Rule Published on GitHub

A critical detection rule for a Budibase authentication bypass vulnerability has been published on GitHub. The rule, designed for security monitoring systems, specifically targets CVE-2026-31816, which allows attackers to gain unauthenticated access to protected endpoints. The exploit hinges on a flawed authorization middleware that improperly processes requests containing the `/webhooks/trigger` pattern within the query string, effectively bypassing security checks.

The technical rule is configured to scan the full URI, including the query string, for the presence of the `/webhooks/trigger` pattern. It employs `lowercase` and `urldecode` transforms to catch case-insensitive and encoded variants, using a `contains` match type for maximum flexibility. The rule's metadata correctly references the associated CVE, MITRE ATT&CK techniques, and CWE (Common Weakness Enumeration) classifications, providing a direct signature for security teams to implement.

This public release of a detection signature signals active scrutiny of the Budibase platform's security posture. For organizations using Budibase, the availability of this rule is a critical step for immediate threat detection and mitigation, applying direct pressure to patch vulnerable deployments. The rule's specificity and public nature highlight the ongoing need for robust input validation in web application middleware to prevent such authorization failures.