Tenable Terrascan up to 1.18.3 File Scan Endpoint webhook_url server-side request forgery

Summaryinfo

A vulnerability was found in Tenable Terrascan up to 1.18.3 and classified as critical. Impacted is an unknown function of the file /v1/{iac}/{iacVersion}/{cloud}/local/file/scan of the component File Scan Endpoint. Executing a manipulation of the argument webhook_url can lead to server-side request forgery. This vulnerability is tracked as CVE-2026-47356. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Tenable Terrascan up to 1.18.3. It has been declared as critical. This vulnerability affects an unknown code of the file /v1/{iac}/{iacVersion}/{cloud}/local/file/scan of the component File Scan Endpoint. The manipulation of the argument webhook_url with an unknown input leads to a server-side request forgery vulnerability. The CWE definition for the vulnerability is CWE-918. 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. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Terrascan v1.18.3 and prior are vulnerable to Server-Side Request Forgery (SSRF) via the webhook_url parameter in the file scan endpoint (POST /v1/{iac}/{iacVersion}/{cloud}/local/file/scan) when running in server mode. An unauthenticated remote attacker can supply an arbitrary URL as the webhook_url multipart form parameter. After scanning the uploaded file, Terrascan sends an HTTP POST request to the attacker-controlled URL containing the full scan results as a JSON body, with the attacker-supplied webhook_token forwarded as a Bearer token in the Authorization header. The retryable HTTP client retries up to 10 times on failure. 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.

The weakness was disclosed by Tristan Madani. The advisory is shared for download at github.com. This vulnerability was named CVE-2026-47356 since 05/19/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/23/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Tenable

Name

• Terrascan

Version

• 1.18.0
• 1.18.1
• 1.18.2
• 1.18.3

License

• free

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