{"id":"GHSA-mqpr-49jj-32rc","summary":"n8n: Webhook Forgery on Github Webhook Trigger","details":"## Impact\nAn attacker who knows the webhook URL of a workflow using the GitHub Webhook Trigger node could send unsigned POST requests and trigger the workflow with arbitrary data. The node did not implement the HMAC-SHA256 signature verification that GitHub provides to authenticate webhook deliveries, allowing any party to spoof GitHub webhook events.\n\n## Patches\nThe issue has been fixed in n8n versions 2.5.0 and 1.123.15. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Limit workflow creation and editing permissions to fully trusted users only.\n- Restrict network access to the n8n webhook endpoint to known GitHub webhook IP ranges.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","aliases":["CVE-2026-56357"],"modified":"2026-07-18T17:45:20.568532301Z","published":"2026-02-26T15:58:34Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-02-26T15:58:34Z","nvd_published_at":"2026-06-22T22:16:52Z","cwe_ids":["CWE-290"],"severity":"MODERATE"},"references":[{"type":"WEB","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":"WEB","url":"https://github.com/n8n-io/n8n/commit/a19347a6bc9a96d5065ac77d25a811e46178c578"},{"type":"WEB","url":"https://github.com/n8n-io/n8n/commit/afe322325502f448b33bff1db1575e4447c28a36"},{"type":"PACKAGE","url":"https://github.com/n8n-io/n8n"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger"}],"affected":[{"package":{"name":"n8n","ecosystem":"npm","purl":"pkg:npm/n8n"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.123.15"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-mqpr-49jj-32rc/GHSA-mqpr-49jj-32rc.json"}},{"package":{"name":"n8n","ecosystem":"npm","purl":"pkg:npm/n8n"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.5.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-mqpr-49jj-32rc/GHSA-mqpr-49jj-32rc.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N"}]}