Terrascan <=1.18.3 SSRF via URL resolution in server mode
CVE-2026-47358 Published on May 19, 2026
Terrascan v1.18.3 and prior are vulnerable to Server-Side Request Forgery (SSRF) via external URL resolution in uploaded IaC templates when running in server mode. When Terrascan parses uploaded ARM templates or CloudFormation templates, it resolves external URLs referenced within those templates via hashicorp/go-getter with all default detectors enabled, including FileDetector. An unauthenticated remote attacker can upload an ARM template containing a templateLink.uri or parametersLink.uri field, or a CloudFormation template containing an AWS::CloudFormation::Stack TemplateURL field, pointing to an attacker-controlled URL. Terrascan will fetch the attacker-controlled URL server-side. Unlike SSRF via the remote scan endpoint, file:// URLs are directly usable without requiring an X-Terraform-Get redirect, enabling local file read. This affects deployments running terrascan in server mode (terrascan server), which binds to 0.0.0.0 with no authentication. Note: Terrascan was archived in August 2023 and no patch will be released.
Weakness Types
What is a SSRF Vulnerability?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
CVE-2026-47358 has been classified to as a SSRF vulnerability or weakness.
Externally Controlled Reference to a Resource in Another Sphere
The product uses an externally controlled name or reference that resolves to a resource that is outside of the intended control sphere.
External Control of File Name or Path
The software allows user input to control or influence paths or file names that are used in filesystem operations.
Affected Versions
tenable Terrascan:- Before and including 1.18.3 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.