{"id":"CVE-2026-56357","aliases":["EUVD-2026-38377","GHSA-mqpr-49jj-32rc"],"status":"published","title":"n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger","description":"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.","severity":{"version":"4.0","score":6.3,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00314,"percentile":0.24636,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-290"],"published":"2026-02-26T15:58:34Z","modified":"2026-10-28T02:31:06Z","fixes":[{"ecosystem":"npm","package":"n8n","fixed_in":["1.123.15","2.5.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.123.15"}]}]},{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.0.0"},{"fixed":"2.5.0"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.123.15"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.5.0"}]}]}],"products":[{"vendor":"n8n","product":"n8n"},{"vendor":"n8n-io","product":"n8n"}],"references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc","tags":["vendor-advisory","Vendor Advisory","advisory","web"]},{"url":"https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger","tags":["third-party-advisory","Third Party Advisory","advisory","web"]},{"url":"https://github.com/n8n-io/n8n/commit/a19347a6bc9a96d5065ac77d25a811e46178c578","tags":["web"]},{"url":"https://github.com/n8n-io/n8n/commit/afe322325502f448b33bff1db1575e4447c28a36","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56357","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-mqpr-49jj-32rc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56357.json","tags":["advisory"]},{"url":"https://github.com/n8n-io/n8n","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-56357","title":"n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger","description":"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.","status":"published","published":"2026-06-22T21:04:52.333Z","modified":"2026-06-23T14:25:03.009Z","cvss":[{"version":"4.0","score":6.3,"vector":"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","level":"medium","assessor":"cna"},{"version":"3.1","score":4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T13:37:02.780526Z"}],"euvd":[{"id":"EUVD-2026-38377","description":"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.","status":"published","published":"2026-06-22T21:04:52Z","modified":"2026-06-23T14:25:03Z","cvss":[{"version":"4.0","score":6.3,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T18:20:33.324654Z"}],"ghsa":[{"id":"GHSA-mqpr-49jj-32rc","title":"n8n: Webhook Forgery on Github Webhook Trigger","description":"## 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.","status":"published","published":"2026-02-26T15:58:34Z","modified":"2026-07-18T17:29:02Z","cvss":[{"version":"4.0","score":6.3,"vector":"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","level":"medium"},{"version":"3.1","score":4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T14:40:46.257074Z"}],"nvd":[{"id":"CVE-2026-56357","description":"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.","status":"published","published":"2026-06-22T22:16:52.51Z","modified":"2026-06-24T16:47:01.937Z","cvss":[{"version":"4.0","score":6.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T14:12:25.288279Z"}],"osv":[{"id":"CVE-2026-56357","title":"n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger","description":"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.","status":"published","published":"2026-06-22T21:04:52.333Z","modified":"2026-10-28T02:31:06.786366678Z","cvss":[{"version":"4.0","score":6.3,"vector":"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","level":"medium"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T15:45:11.609219Z"},{"id":"GHSA-mqpr-49jj-32rc","title":"n8n: Webhook Forgery on Github Webhook Trigger","description":"## 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.","status":"published","published":"2026-02-26T15:58:34Z","modified":"2026-07-18T17:45:20.568532301Z","cvss":[{"version":"3.1","score":4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"},{"version":"4.0","score":6.3,"vector":"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","level":"medium"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T15:46:52.170928Z"}]}}