{"id":"CVE-2026-56360","aliases":["EUVD-2026-42258","GHSA-38c7-23hj-2wgq","GHSA-wgjf-2hg5-2533"],"status":"published","title":"n8n - Webhook Forgery via Unsigned POST Requests in ZendeskTrigger","description":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.","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":"2026-02-26T22:47:06Z","modified":"2026-10-28T02:31:03Z","fixes":[{"ecosystem":"npm","package":"n8n","fixed_in":["1.123.18","2.6.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.123.18"}]}]},{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.0.0"},{"fixed":"2.6.2"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.123.18"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.6.2"}]}]}],"products":[{"vendor":"n8n","product":"n8n"},{"vendor":"n8n-io","product":"n8n"}],"references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-38c7-23hj-2wgq","tags":["vendor-advisory","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-unsigned-post-requests-in-zendesktrigger","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://github.com/n8n-io/n8n/commit/3839e310bd4c3002c646c363d1411916fa195151","tags":["web"]},{"url":"https://github.com/n8n-io/n8n/commit/c6520e4e87614fa60c9433e93019e211f19f65f9","tags":["web"]},{"url":"https://github.com/advisories/GHSA-38c7-23hj-2wgq"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56360","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-wgjf-2hg5-2533"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56360.json","tags":["advisory"]},{"url":"https://github.com/n8n-io/n8n","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-56360","title":"n8n - Webhook Forgery via Unsigned POST Requests in ZendeskTrigger","description":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.","status":"published","published":"2026-07-08T13:49:03.453Z","modified":"2026-07-08T14:26:33.242Z","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":"2026-11-02T13:36:51.6229Z"}],"euvd":[{"id":"EUVD-2026-42258","description":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.","status":"published","published":"2026-07-08T13:49:03Z","modified":"2026-07-08T14:26:33Z","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":"2026-11-02T18:20:10.578977Z"}],"ghsa":[{"id":"GHSA-38c7-23hj-2wgq","title":"n8n has Webhook Forgery on Zendesk Trigger Node","description":"## Impact\nAn attacker who knows the webhook URL of a workflow using the ZendeskTrigger node could send unsigned POST requests and trigger the workflow with arbitrary data. The node does not verify the HMAC-SHA256 signature that Zendesk attaches to every outbound webhook, allowing any party to inject crafted payloads into the connected workflow.\n\n## Patches\nThe issue has been fixed in n8n versions 2.6.2 and 1.123.18. 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 Zendesk IP ranges.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","status":"published","published":"2026-02-26T22:47:06Z","modified":"2026-02-26T22:47:06Z","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":"2026-11-02T14:39:27.949248Z"},{"id":"GHSA-wgjf-2hg5-2533","title":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks...","description":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.","status":"published","published":"2026-07-08T15:32:01Z","modified":"2026-07-08T15:32:07Z","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"},{"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":"2026-11-02T15:09:20.268554Z"}],"nvd":[{"id":"CVE-2026-56360","description":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.","status":"published","published":"2026-07-08T14:17:16.757Z","modified":"2026-10-25T20:10:00.147Z","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"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T14:12:28.040501Z"}],"osv":[{"id":"CVE-2026-56360","title":"n8n - Webhook Forgery via Unsigned POST Requests in ZendeskTrigger","description":"n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.","status":"published","published":"2026-07-08T13:49:03.453Z","modified":"2026-10-28T02:31:03.572899536Z","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-38c7-23hj-2wgq","title":"n8n has Webhook Forgery on Zendesk Trigger Node","description":"## Impact\nAn attacker who knows the webhook URL of a workflow using the ZendeskTrigger node could send unsigned POST requests and trigger the workflow with arbitrary data. The node does not verify the HMAC-SHA256 signature that Zendesk attaches to every outbound webhook, allowing any party to inject crafted payloads into the connected workflow.\n\n## Patches\nThe issue has been fixed in n8n versions 2.6.2 and 1.123.18. 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 Zendesk IP ranges.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","status":"published","published":"2026-02-26T22:47:06Z","modified":"2026-07-09T04:11:38.193852913Z","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":"2026-11-02T15:46:35.406455Z"}]}}