{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-41896: Coolify: Unauthenticated Deployment Trigger via Webhook HMAC Bypass with Null Secret","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-41896","status":"final","version":"1","initial_release_date":"2026-06-29T20:16:50.951Z","current_release_date":"2026-06-29T20:16:50.951Z","revision_history":[{"date":"2026-06-29T20:16:50.951Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-41896 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-41896"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-41896"},{"category":"external","summary":"https://github.com/coollabsio/coolify/security/advisories/GHSA-w8wm-r924-f65v","url":"https://github.com/coollabsio/coolify/security/advisories/GHSA-w8wm-r924-f65v"}]},"product_tree":{"branches":[{"category":"vendor","name":"coollabsio","branches":[{"category":"product_name","name":"coolify","branches":[{"category":"product_version","name":"< 4.0.0-beta.474","product":{"name":"coollabsio coolify < 4.0.0-beta.474","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:coollabsio:coolify:\\<_4.0.0-beta.474:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-41896","title":"Coolify: Unauthenticated Deployment Trigger via Webhook HMAC Bypass with Null Secret","notes":[{"category":"description","text":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}