# CVE-2026-41896

> Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to 4.0.0-beta.474, the HMAC key is the application's manual_webhook_secret_github field, which is used by Coolify's webhook endpoints to validate incoming requests, is nullable with no default — meaning newly created applications have a null webhook secret. PHP's hash_hmac() function silently coerces a null key to an empty string ''. So when the secret is null, the server computes hash_hmac('sha256', $payload, '') — a deterministic value that any attacker can calculate independently. By se

- **CVSS:** 7.5 (HIGH)
- **EPSS:** 0.2%
- **CWE:** CWE-287

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-41896
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