CVE-2026-47358: tenable terrascan External Control of File Name or Path

Vulnerability summary

CVE-2026-47358 is a critical (CVSS 9.3) External Control of File Name or Path vulnerability in tenable terrascan. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.1% of scored vulnerabilities.

Timeline

1. 19-05-2026
   PublishedVulnerability first disclosed.
2. 19-05-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-73External Control of File Name or PathThe product allows user input to control or influence paths or file names that are used in filesystem operations.
• CWE-610Externally Controlled Reference to a Resource in Another SphereThe product uses an externally controlled name or reference that resolves to a resource that is outside of the intended control sphere.
• CWE-918Server-Side Request Forgery (SSRF)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.