Vulnerability Description
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 sending X-Hub-Signature-256: sha256=<hash_hmac('sha256', payload, '')>, an unauthenticated attacker can forge a valid signature and trigger deployments. This vulnerability is fixed in 4.0.0-beta.474.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/coollabsio/coolify/security/advisories/GHSA-w8wm-r924-f65v
- https://github.com/coollabsio/coolify/security/advisories/GHSA-w8wm-r924-f65v
FAQ
What is CVE-2026-41896?
CVE-2026-41896 is a vulnerability with a CVSS score of 7.5 (HIGH). 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...
How severe is CVE-2026-41896?
CVE-2026-41896 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-41896?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.