CVE-2026-25631: 
NixOS vulnerability analysis and mitigation

CVE-2026-25631 is a domain allowlist bypass vulnerability in n8n, an open-source workflow automation platform, that allows authenticated attackers to send HTTP requests with credentials to unintended domains, potentially leading to credential exfiltration. The flaw affects all n8n versions prior to 1.121.0 and was published on February 6, 2026. It carries a CVSS v3.1 base score of 6.5 (Medium) and a CVSS v4.0 base score of 5.3 (Medium) (GitHub Advisory, Red Hat CVE).

The vulnerability stems from improper input validation (CWE-20) and insufficiently protected credentials (CWE-522) in the HTTP Request node's credential domain validation logic. Specifically, the validation fails to correctly enforce domain restrictions when wildcard patterns (e.g., *.example.com) are configured in the "Allowed domains" setting, allowing an attacker to craft requests that bypass the allowlist and route credentials to attacker-controlled domains. Exploitation requires only low-level authenticated access to the n8n instance and no user interaction, making it straightforward for any authenticated user to abuse (GitHub Advisory).

Successful exploitation results in a high confidentiality impact — stored credentials (such as API keys, tokens, or passwords) associated with HTTP Request node configurations can be exfiltrated to attacker-controlled domains. There is no integrity or availability impact. The vulnerability is scoped to users who have configured wildcard domain patterns in their HTTP Request credentials, limiting the affected population but potentially exposing sensitive third-party service credentials to unauthorized parties (GitHub Advisory, Red Hat CVE).

No public proof-of-concept exploit code or evidence of in-the-wild exploitation has been reported as of the time of writing. The EPSS score is approximately 0.084%, indicating a low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. No threat actor attribution has been identified (GitHub Advisory).

1. Reconnaissance: Identify an n8n instance running a version prior to 1.121.0 that is accessible and has HTTP Request nodes configured with wildcard domain patterns (e.g., *.example.com) in the "Allowed domains" credential setting.
2. Obtain authenticated access: Log in to the n8n instance using a valid low-privileged account (e.g., a regular user account).
3. Create or modify a workflow: Create a new workflow (or modify an existing one if permitted) that uses an HTTP Request node configured with the target credentials that have wildcard domain restrictions.
4. Craft a bypass request: Configure the HTTP Request node to send a request to an attacker-controlled domain that matches the wildcard pattern (e.g., attacker.example.com or a subdomain-like bypass) but routes traffic to an external server under attacker control.
5. Trigger the workflow: Execute the workflow, causing n8n to send the HTTP request — including the attached credentials — to the attacker-controlled endpoint.
6. Capture credentials: Collect the exfiltrated credentials (e.g., API keys, tokens, or Basic Auth headers) from the attacker-controlled server's request logs (GitHub Advisory).

• Logs: n8n workflow execution logs showing HTTP Request node activity sending requests to unexpected or external domains not explicitly listed in the allowed domains configuration.
• Network: Outbound HTTP/HTTPS requests from the n8n server to unfamiliar or attacker-controlled domains carrying Authorization headers or credential-bearing payloads.
• Application: Audit logs showing new workflow creation or modification by low-privileged users, particularly involving HTTP Request nodes with domain-restricted credentials.
• Configuration: HTTP Request node credentials configured with wildcard domain patterns (e.g., *.example.com) that could be abused for domain bypass.

Users should upgrade n8n to version 1.121.0 or later, which contains the fix for this vulnerability (GitHub Advisory). For those unable to upgrade immediately, the following workarounds are recommended:

• Replace all wildcard domain patterns (e.g., *.example.com) in HTTP Request credentials with explicit, fully-qualified domain listings.
• Review and restrict workflow creation and modification permissions to trusted users only.
• Audit existing workflows that use HTTP Request nodes with domain-restricted credentials to identify potential misuse.

The vulnerability was credited to researcher weblover12 and disclosed via GitHub's security advisory program by n8n maintainer csuermann on February 4, 2026. The Hacker News published coverage of n8n security issues around the same disclosure period (The Hacker News). No significant broader community debate or social media controversy has been observed for this specific CVE.