CVE-2026-118640 in n8n
Summary
by MITRE • 10/28/2026
n8n before 1.123.85, 2.43.5, and 2.44.1 contains an authorization bypass vulnerability in Chat Hub that allows chat-only users to register restricted tool types. Users with the global:chatUser role can add and run tools through chat to execute sandboxed code, access permitted files, and use instance workflows, Data Tables, and agents.
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Analysis
by VulDB Data Team • 10/28/2026
The identified security flaw resides within n8n versions prior to 1.123.85, 2.43.5, and 2.44.1, specifically affecting the Chat Hub component of the platform. This vulnerability constitutes a critical authorization bypass that undermines the intended access control mechanisms designed for users assigned the global:chatUser role. In standard operational contexts, chat-only users are granted limited privileges to interact with the system through conversational interfaces, allowing them to execute sandboxed code, access permitted files, and utilize instance workflows, Data Tables, and agents within a constrained environment. However, the vulnerability exposes a logic error in how tool registration is validated against user roles, enabling these restricted users to register and invoke tool types that should be inaccessible under normal security policies.
From a technical perspective, the flaw arises because the system fails to properly enforce role-based access control when processing requests related to tool type registration via the Chat Hub interface. While the application correctly restricts certain administrative or high-privilege actions for chat users, it inadvertently allows them to bypass these restrictions by exploiting inconsistencies in how new tools are defined and linked to execution contexts. This misconfiguration permits a user with only chat permissions to introduce restricted tool types into their operational scope. Once registered, these tools can be executed through the same conversational interface used for standard operations, effectively elevating the user's capabilities beyond what is permitted by their assigned role.
The operational impact of this vulnerability is significant as it allows an attacker or malicious insider with chat access to expand their attack surface within the n8n instance. By registering restricted tool types, a compromised account can potentially execute arbitrary code in contexts that may not be as strictly sandboxed as standard chat executions, access sensitive data through Data Tables intended for higher-privileged roles, and trigger workflows designed for administrative tasks. This escalation of privilege compromises the integrity of the automation platform's security model, leading to potential unauthorized data exposure, manipulation of business logic, or further lateral movement within the connected systems that n8n manages.
This issue aligns with CWE-269, which describes Improper Privilege Management, as it involves a failure to enforce proper access control levels for different user roles. Additionally, from an adversary perspective, this vulnerability facilitates privilege escalation techniques documented in MITRE ATT&CK framework under tactics such as Initial Access and Execution, where attackers leverage misconfigured permissions to gain higher-level access or execute unauthorized commands within the environment. The ability to register restricted tools effectively bypasses the principle of least privilege, allowing low-privileged users to perform actions reserved for administrators or power users.
To mitigate this vulnerability, organizations running affected versions of n8n must upgrade immediately to version 1.123.85, 2.43.5, or later, where these authorization checks have been corrected. Until the update is applied, it is advisable to restrict access to the Chat Hub interface exclusively to trusted users with appropriate administrative privileges and to monitor logs for unusual patterns of tool registration or execution by chat-only accounts. Implementing strict network segmentation and ensuring that only necessary services are exposed can also help limit the potential impact if an attacker attempts to exploit this flaw in a live environment. Regular auditing of user roles and permissions is recommended to ensure alignment with organizational security policies and to detect any unauthorized privilege escalations promptly.