CVE-2026-63769: Huginn SSRF Vulnerability

CVE-2026-63769 Overview

CVE-2026-63769 is a Server-Side Request Forgery (SSRF) vulnerability [CWE-918] affecting Huginn through version 2022.08.18. The flaw resides in the fetch_url method of ScenarioImport, which fails to validate user-supplied URLs before issuing HTTP requests. Authenticated users can submit crafted URLs that force the server to send requests to arbitrary destinations, including internal network services and cloud metadata endpoints. Attackers can enumerate internal ports through error signatures and retrieve sensitive credentials from Instance Metadata Service (IMDS) endpoints on AWS, Azure, and GCP deployments.

Critical Impact
Authenticated attackers can pivot from a Huginn instance to internal infrastructure and cloud metadata services, exposing credentials and enabling lateral movement into otherwise isolated environments.

Affected Products

Huginn versions through 2022.08.18
Self-hosted Huginn deployments running the vulnerable ScenarioImport component
Cloud-hosted Huginn instances with access to instance metadata endpoints

Discovery Timeline

2026-07-20 - CVE-2026-63769 published to the National Vulnerability Database
2026-07-23 - Last updated in NVD database

Technical Details for CVE-2026-63769

Vulnerability Analysis

The vulnerability stems from insufficient validation in Huginn's scenario import functionality. When a user imports a scenario by URL, the fetch_url method of ScenarioImport issues an outbound HTTP request to retrieve the referenced JSON payload. The method does not restrict the destination host, scheme, or IP range. Attackers can supply URLs pointing to 127.0.0.1, RFC1918 address space, link-local addresses, or cloud metadata endpoints such as 169.254.169.254.

Responses and error messages returned by the application leak information about internal services. Differences between connection timeouts, refused connections, and HTTP-level errors allow attackers to fingerprint internal hosts and enumerate open ports. On cloud-hosted deployments, the server can be coerced into fetching IAM role credentials from the metadata service, granting the attacker programmatic access to cloud APIs.

Exploitation requires authenticated access but no elevated privileges, since any user permitted to import scenarios can trigger the flaw.

Root Cause

The root cause is missing URL validation and host allowlisting in the fetch_url method. Huginn accepts arbitrary destinations and follows HTTP redirects without filtering internal address ranges or restricting the URL scheme.

Attack Vector

An authenticated attacker submits a scenario import request containing a URL that targets internal infrastructure. The Huginn server processes the request from its own network position, bypassing perimeter controls. Responses returned to the attacker reveal the state of the targeted endpoint, and successful requests to metadata services return raw credential material.

No public exploit code has been released for this vulnerability. Refer to the VulnCheck Security Advisory and the GitHub Pull Request for technical details on the fix.

Detection Methods for CVE-2026-63769

Indicators of Compromise

Outbound HTTP requests from the Huginn application server to 169.254.169.254, metadata.google.internal, or metadata.azure.com
Scenario import activity referencing URLs pointing to loopback, link-local, or RFC1918 address ranges
Unexpected HTTP requests originating from the Huginn process to internal service ports such as 6379, 5432, 3306, or 8080
Application logs showing repeated ScenarioImport requests with varying host or port values consistent with port scanning

Detection Strategies

Inspect Huginn application logs for ScenarioImport events and correlate the submitted URL against an allowlist of expected external hosts
Monitor egress traffic from the Huginn host and alert on connections to metadata IP addresses or private network ranges
Deploy web application firewall rules that block scenario import payloads containing internal IP literals or reserved hostnames

Monitoring Recommendations

Enable audit logging for authenticated user actions, particularly scenario imports, and forward logs to a centralized analytics platform
Alert on spikes in outbound HTTP 4xx or 5xx responses from the Huginn server, which may indicate active port enumeration
Track cloud IAM API calls originating from the Huginn instance role for anomalous activity such as new access key creation or resource enumeration

How to Mitigate CVE-2026-63769

Immediate Actions Required

Upgrade Huginn to a version that includes the fix merged in GitHub Pull Request #3684
Restrict which authenticated users can perform scenario imports by reviewing account roles and removing unnecessary permissions
Enforce IMDSv2 with hop-limit restrictions on AWS-hosted deployments to prevent SSRF-based credential theft
Rotate any cloud IAM credentials associated with the Huginn instance role if exploitation is suspected

Patch Information

The upstream fix is tracked in the Huginn repository through GitHub Issue #3679 and merged via Pull Request #3684. Administrators running self-hosted deployments should pull the latest main branch or a release incorporating the patch. Additional context is available in the VulnCheck Security Advisory.

Workarounds

Place Huginn behind an egress proxy that denies connections to loopback, link-local, and RFC1918 destinations
Apply host-based firewall rules blocking outbound traffic from the Huginn process to 169.254.169.254 and other metadata endpoints
Deploy Huginn in a network segment without direct access to sensitive internal services or cloud metadata APIs
Require IMDSv2 session tokens on AWS and set the metadata response hop limit to 1

bash

# AWS CLI: enforce IMDSv2 and restrict hop limit on the Huginn EC2 instance
aws ec2 modify-instance-metadata-options \
  --instance-id i-0123456789abcdef0 \
  --http-tokens required \
  --http-put-response-hop-limit 1 \
  --http-endpoint enabled