CVE-2026-110846 in n8n
Summary
by MITRE • 10/15/2026
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a signature bypass in the waiting-webhook endpoint, which selects Send-and-Wait validation before normalising an alternate node reference form. Attackers holding an execution's resume token can approve waiting executions meant for others, running downstream actions under the workflow owner's credentials, potentially including command execution.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability identified in n8n versions prior to 2.41.4 and version 2.42.x prior to 2.42.1 represents a critical authentication bypass within the waiting-webhook endpoint logic. This flaw stems from an incorrect ordering of validation steps during request processing, specifically involving how alternate node reference forms are handled relative to Send-and-Wait execution states. In normal operation, n8n workflows often utilize a Send-and-Wait pattern where an initial HTTP trigger sends data and pauses workflow execution until a subsequent webhook call resumes it with specific credentials or tokens. The security architecture relies on strict validation of the resume token associated with that paused execution to ensure that only authorized parties can proceed. However, in the affected versions, the system prioritizes normalizing alternate node reference forms before performing the necessary signature verification for Send-and-Wait validations. This sequencing error creates a window where an attacker who possesses a valid execution's resume token can manipulate the request context to bypass intended access controls.
From a technical perspective, this is classified as CWE-287 Improper Authentication because the system fails to correctly verify the identity of the user before granting them permission to execute workflow actions. The core issue lies in the race condition or logical flaw where the normalization process alters how the request parameters are interpreted, allowing an attacker to associate their resume token with a different execution context than intended. By exploiting this misalignment, an individual can approve waiting executions that were originally queued for other users or workflows. This effectively allows unauthorized actors to impersonate legitimate workflow owners by leveraging stolen or leaked resume tokens. The impact is severe because it circumvents the isolation boundaries between distinct workflow instances and user accounts within the automation platform.
The operational impact of this vulnerability extends beyond simple data access, posing a significant risk for remote code execution scenarios. Since n8n workflows can be configured to perform a wide array of actions including API calls, database updates, and script executions, an attacker who successfully bypasses authentication can trigger downstream actions under the credentials of the workflow owner. If the compromised workflow includes nodes that execute system commands or interact with insecure internal services, this leads directly to CWE-94 Improper Control of Generation of Code Command Injection. The attacker gains the ability to run arbitrary code on the server hosting n8n, potentially leading to full system compromise, data exfiltration, and lateral movement within the network infrastructure. This is particularly dangerous in enterprise environments where automation workflows often hold high privileges for integration with critical business systems.
To mitigate this risk, organizations running affected versions of n8n must immediately upgrade to version 2.41.4 or later, or specifically to version 2.42.1 and above, which corrects the validation sequence in the waiting-webhook endpoint. Until an upgrade is feasible, administrators should implement strict network-level access controls such as IP whitelisting for webhook endpoints if possible, although this may not fully mitigate token theft scenarios. Additionally, reviewing workflow configurations to minimize the use of high-privilege credentials in automation nodes can reduce the blast radius of a successful exploitation attempt. Monitoring logs for unusual patterns in resume token usage and webhook invocations can also aid in early detection of potential abuse attempts aligned with ATT&CK technique T1078 Valid Accounts or T1210 Exploitation of Remote Services.