CVE-2026-56360
n8n - Webhook Forgery via Unsigned POST Requests in ZendeskTrigger
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
n8n - Webhook Forgery via Unsigned POST Requests in ZendeskTrigger
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.
- Record
CVE-2026-56360- CVSS 4.0
- 6.3 Medium
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 - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
EUVDEUVD-2026-42258
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.
- Record
EUVD-2026-42258- CVSS 4.0
- 6.3 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-38c7-23hj-2wgq
n8n has Webhook Forgery on Zendesk Trigger Node
Impact
An 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.
Patches
The 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.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Limit workflow creation and editing permissions to fully trusted users only.
- Restrict network access to the n8n webhook endpoint to known Zendesk IP ranges.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- Record
GHSA-38c7-23hj-2wgq- CVSS 4.0
- 6.3 Medium
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 - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
GitHub AdvisoriesGHSA-wgjf-2hg5-2533
n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks...
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.
- Record
GHSA-wgjf-2hg5-2533- CVSS 4.0
- 6.3 Medium
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 - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-56360- CVSS 4.0
- 6.3 Medium
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 - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
OSV
n8n - Webhook Forgery via Unsigned POST Requests in ZendeskTrigger
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.
- Record
CVE-2026-56360- CVSS 4.0
- 6.3 Medium
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 - Weakness
- CWE-290
- Updated
- 2026-11-02
OSVGHSA-38c7-23hj-2wgq
n8n has Webhook Forgery on Zendesk Trigger Node
Impact
An 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.
Patches
The 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.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Limit workflow creation and editing permissions to fully trusted users only.
- Restrict network access to the n8n webhook endpoint to known Zendesk IP ranges.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- Record
GHSA-38c7-23hj-2wgq- CVSS 4.0
- 6.3 Medium
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 - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-56360 is a medium vulnerability (CVSS 6.3) in N8n, published February 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. Fixed in n8n 1.123.18.
References
github.com/n8n-io/n8n/security/advisories/GHSA-38c7-23hj-2wgq
vulncheck.com/advisories/n8n-webhook-forgery-via-unsigned-post-requests-in-zendesktrigger
nvd.nist.gov/vuln/detail/CVE-2026-56360