{"id":"CVE-2026-56357","aliases":["GHSA-mqpr-49jj-32rc"],"url":"https://o3.security/vulnerability/CVE-2026-56357","summary":"n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger","details":"n8n before 1.123.15 and 2.5.0 contains a webhook forgery vulnerability in the GitHub Webhook Trigger node that fails to implement HMAC-SHA256 signature verification. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary data, spoofing GitHub webhook events.","published":"2026-06-22T21:04:52.333Z","modified":"2026-08-07T11:31:26.909646493Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"n8n","fixedVersion":"1.123.15"},{"ecosystem":"npm","name":"n8n","fixedVersion":"2.5.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56357.json"},{"type":"ADVISORY","url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56357"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:26.909646493Z"}}