CVE-2026-103253

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain an approval bypass vulnerability in the Send and Wait node's Approve Within Chat mode. Attackers can submit resume requests without verification of the requester's identity or approval permissions, allowing unauthenticated users to advance waiting executions and trigger guarded actions.

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain a session token leakage vulnerability in the Dynamic Credentials authorize and revoke endpoints. Attackers with resolver registration capability can capture collaborators' session tokens by setting a fallback resolver to an attacker-controlled endpoint during the account connection flow, enabling unauthorized credential access.

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain an unescaped parameter interpolation vulnerability in SendGrid, Freshservice, and ServiceNow nodes that allows attackers to bypass filters by breaking out of query literals. Attackers can exploit this by binding vulnerable node parameters to untrusted external input to widen single-record lookups into match-all queries, exposing bulk data including contact lists, tickets, and directory entries.

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a path traversal vulnerability in the n8n node that fails to validate resource identifiers. Attackers can craft malicious resource IDs to redirect API calls to unintended resources, allowing unauthorized access to workflows, executions, and credential secrets within the API key's scope.

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain a credentials leak vulnerability in the Wekan and Baserow username-and-password credentials that sends unencrypted passwords to unvalidated hosts. Attackers with credential update permissions can modify the host field to receive account passwords at arbitrary hosts, bypassing domain validation controls.

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a path traversal vulnerability in signed resume URL generation for Send-and-Wait approvals. Attackers with workflow creation permissions can mint valid approval URLs for gates in projects they cannot access by exploiting unresolved traversal sequences in caller-controlled node IDs, enabling cross-project approval forgery.

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain an authorization bypass vulnerability in the credential test endpoint that resolves project-scoped variables without validating caller access. Attackers can specify an arbitrary project ID in the request body to interpolate sensitive variables into credential test requests sent to attacker-controlled hosts for exfiltration.

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a validation bypass vulnerability in the community package installation handler for queue mode deployments. Attackers with Redis write access can bypass name validation, permission checks, checksum verification, and npm safety checks to install arbitrary npm packages across all cluster instances without authentication.

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a NoSQL injection vulnerability in the MongoDB Chat Memory node that fails to validate the sessionId parameter. Unauthenticated attackers can supply MongoDB query operators in the sessionId field to access conversation histories from other users and perform unauthorized write and delete operations.

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a stored DOM cross-site scripting vulnerability in Resource Locator parameter dropdown link handling. Workflow authors can inject malicious script URLs that execute arbitrary JavaScript in the editor origin when other users open the node dropdown and click the external-link icon, with the payload persisting across workflow imports and shares.