CVE intelligence and bounded remediation

CVE-2026-47358 — Tenable Terrascan security vulnerability

Critical CVSS 9.2

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.

Severity
Critical
CVSS
9.2 (4.0)
Published
2026-05-19
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-73, CWE-610, CWE-918

Affected products

  • tenable / terrascan

Matched remediation archetype

Server-side request forgery and unintended proxying

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
  • Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
  • Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.

Remediate safely

  • Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
  • Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
  • Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.

Authoritative sources

Complete CVE record and remediation plan

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