CVE-2026-41896: CWE-287: Improper Authentication in coollabsio coolify
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.
AI Analysis
Technical Summary
Coolify, an open-source server and application management tool, had a vulnerability (CWE-287) in versions before 4.0.0-beta.474 where the manual_webhook_secret_github field used as the HMAC key for webhook validation could be null. PHP's hash_hmac() function treats a null key as an empty string, resulting in a deterministic HMAC value that attackers can replicate. By sending a forged X-Hub-Signature-256 header with the predictable hash, attackers can bypass authentication and trigger deployments without authorization. This vulnerability is addressed in version 4.0.0-beta.474.
Potential Impact
An unauthenticated attacker can forge webhook signatures due to the null webhook secret key being treated as an empty string in HMAC calculations. This allows the attacker to trigger unauthorized deployments, impacting the integrity of the deployment process. There is no confidentiality or availability impact reported.
Mitigation Recommendations
Upgrade to Coolify version 4.0.0-beta.474 or later, where this vulnerability is fixed. Patch status is not explicitly stated but the fix is included starting from 4.0.0-beta.474. Until upgraded, ensure that the manual_webhook_secret_github field is never null and is properly set to a secure secret to prevent exploitation.
CVE-2026-41896: CWE-287: Improper Authentication in coollabsio coolify
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 v3.1
Score 7.5high
Affected software
pkg:github/coollabsio/coolifyRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Coolify, an open-source server and application management tool, had a vulnerability (CWE-287) in versions before 4.0.0-beta.474 where the manual_webhook_secret_github field used as the HMAC key for webhook validation could be null. PHP's hash_hmac() function treats a null key as an empty string, resulting in a deterministic HMAC value that attackers can replicate. By sending a forged X-Hub-Signature-256 header with the predictable hash, attackers can bypass authentication and trigger deployments without authorization. This vulnerability is addressed in version 4.0.0-beta.474.
Potential Impact
An unauthenticated attacker can forge webhook signatures due to the null webhook secret key being treated as an empty string in HMAC calculations. This allows the attacker to trigger unauthorized deployments, impacting the integrity of the deployment process. There is no confidentiality or availability impact reported.
Mitigation Recommendations
Upgrade to Coolify version 4.0.0-beta.474 or later, where this vulnerability is fixed. Patch status is not explicitly stated but the fix is included starting from 4.0.0-beta.474. Until upgraded, ensure that the manual_webhook_secret_github field is never null and is properly set to a secure secret to prevent exploitation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-22T15:11:54.671Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a42de5d27e9c79719807160
Added to database: 06/29/2026, 21:06:37 UTC
Last enriched: 06/29/2026, 21:21:15 UTC
Last updated: 06/30/2026, 02:26:20 UTC
Views: 7
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