N8n (< 1.123.43) — CraftedSignal Threat Feed

n8n Cross-User Authorization Bypass in Dynamic Credential OAuth Endpoints (CVE-2026-45732)

hello@craftedsignal.io — Thu, 14 May 2026 16:25:42 +0000

A cross-user authorization bypass vulnerability exists in n8n’s Dynamic Credential OAuth endpoints. Specifically, the OAuth1 and OAuth2 credential reconnect endpoints incorrectly authorized access using credential:read instead of the necessary credential:update permission. This flaw allows an authenticated user with only read-only access to a shared credential to initiate an OAuth reconnect flow. By doing so, the attacker can overwrite the stored token material for the credential with tokens bound to an external account under their control. This can lead to workflows relying on the compromised credential executing under the attacker’s OAuth identity. The issue affects n8n versions before 1.123.43, versions between 2.0.0-rc.0 and 2.20.7, and versions between 2.21.0 and 2.21.1.

Attack Chain

An attacker gains access to an n8n instance with shared credentials.
The attacker identifies a shared credential to which they have read-only access.
The attacker navigates to the OAuth1 or OAuth2 credential reconnect endpoint for the target credential.
Due to the authorization bypass (CVE-2026-45732), the attacker is able to initiate an OAuth reconnect flow despite lacking update permissions.
The attacker authenticates with their own external OAuth provider account.
The attacker’s OAuth tokens are used to overwrite the existing tokens for the shared credential.
Workflows using the shared credential now execute under the attacker’s OAuth identity.
The attacker can exfiltrate data to attacker-controlled external services or maintain persistent access to shared integrations.

Impact

Successful exploitation of this vulnerability (CVE-2026-45732) allows an attacker to overwrite OAuth tokens in shared credentials, leading to data exfiltration to attacker-controlled external services. This can result in persistent takeover of shared integrations, potentially impacting multiple users or projects that rely on the compromised credential. The affected instances are those where credentials are shared with other users or across projects, creating a significant risk of unauthorized access and data breaches.

Recommendation

Upgrade n8n to version 1.123.43, 2.20.7, 2.21.1, or later to remediate CVE-2026-45732 as advised in the advisory.
If immediate upgrade is not possible, restrict credential sharing to fully trusted users as a temporary mitigation.
Audit shared credentials for unexpected OAuth token changes and revoke any tokens that may have been replaced as an additional short-term measure.

n8n Arbitrary File Read via Git Node (CVE-2026-44790)

hello@craftedsignal.io — Thu, 14 May 2026 16:23:03 +0000

A critical vulnerability, CVE-2026-44790, exists within the n8n workflow automation platform. The vulnerability resides in the Git node’s Push operation, where an authenticated user with permissions to create or modify workflows can inject arbitrary CLI flags. This injection allows the attacker to read arbitrary files from the n8n server’s file system. Successful exploitation can lead to complete compromise of the n8n instance, including access to sensitive data stored on the server, such as credentials, API keys, and internal configuration files. Patches have been released in n8n versions 1.123.43, 2.20.7, and 2.22.1 to address this vulnerability.

Attack Chain

An attacker gains authenticated access to an n8n instance.
The attacker obtains permissions to create or modify workflows within n8n.
The attacker creates or modifies a workflow to include the Git node.
Within the Git node’s configuration, specifically the Push operation, the attacker injects malicious CLI flags. These flags are crafted to read arbitrary files from the server’s file system (e.g., using git --help).
The workflow is executed, and the Git node attempts to perform the Push operation with the injected flags.
Due to the flag injection, the Git command executes with the attacker-supplied arguments.
The attacker retrieves the contents of the targeted file, which may contain sensitive information.
The attacker leverages the stolen information to further compromise the n8n instance or connected systems.

Impact

Successful exploitation of CVE-2026-44790 allows an attacker to read arbitrary files from the n8n server. This can expose sensitive information such as API keys, credentials, configuration files, and other internal data. A successful attack could lead to full compromise of the n8n instance and potentially impact connected systems and data. The severity of the impact is critical due to the potential for complete system takeover and sensitive data exposure.

Recommendation

Upgrade n8n to version 1.123.43, 2.20.7, 2.22.1, or later to patch CVE-2026-44790 as mentioned in the advisory.
Limit workflow creation and editing permissions to only fully trusted users as a short-term workaround.
Deploy the Sigma rule Detect n8n Git Node CLI Injection to identify potential exploitation attempts by monitoring process execution with suspicious Git commands.
Monitor n8n application logs for Git node operations involving unusual command-line arguments, focusing on commands that attempt to read files outside the intended Git repository.

n8n XML Node Prototype Pollution Patch Bypass Leads to RCE

hello@craftedsignal.io — Thu, 14 May 2026 16:22:47 +0000

An authenticated user with permission to create or modify workflows can bypass the patch for GHSA-hqr4-h3xv-9m3r in the XML node of n8n, a workflow automation platform. This vulnerability, identified as CVE-2026-44791, allows for prototype pollution. Successful exploitation, when chained with other nodes, can lead to remote code execution (RCE) on the n8n host. The affected versions include n8n versions prior to 1.123.43, versions 2.21.0 to 2.22.1 (excluding 2.22.1), and versions 2.0.0-rc.0 to 2.20.7 (excluding 2.20.7). This vulnerability matters to defenders because it allows attackers to gain complete control over the n8n instance, potentially compromising sensitive data and enabling further malicious activities.

Attack Chain

An attacker gains authenticated access to an n8n instance with workflow creation and modification privileges.
The attacker crafts a malicious workflow that includes the XML node.
The attacker exploits CVE-2026-44791, bypassing the patch for GHSA-hqr4-h3xv-9m3r by manipulating XML node parameters to inject a prototype pollution payload.
The prototype pollution modifies JavaScript object prototypes within the n8n environment.
The attacker chains the XML node with other nodes in the workflow (e.g., Function node, Execute Command node).
The polluted prototypes are leveraged by the subsequent nodes to execute arbitrary JavaScript code.
The arbitrary code execution allows the attacker to execute system commands on the n8n host.
The attacker achieves remote code execution (RCE), gaining control of the n8n host and potentially compromising the underlying system.

Impact

Successful exploitation of CVE-2026-44791 allows an attacker to achieve remote code execution on the n8n host. This could lead to the complete compromise of the n8n instance, potentially affecting all workflows and data managed by the platform. The attacker could potentially access sensitive information, modify workflows for malicious purposes, or use the compromised host as a pivot point for further attacks within the network. The vulnerability affects n8n instances running vulnerable versions prior to the patched versions, impacting any organization using n8n for workflow automation.

Recommendation

Upgrade n8n to version 1.123.43, 2.20.7, or 2.22.1 or later to remediate CVE-2026-44791, as mentioned in the overview.
Deploy the Sigma rule “Detect n8n XML Node Prototype Pollution Attempt” to identify suspicious workflow creations involving the XML node, as described in the rules section.
If immediate upgrade is not possible, implement the suggested workarounds by limiting workflow creation/editing permissions or disabling the XML node via the NODES_EXCLUDE environment variable, as detailed in the overview section.