Assessment
Why it matters
EPSS is 0.5%; technical severity is CVSS 8.7.
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.
Who should care
- Teams operating Terrascan
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether Terrascan is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Review vendor guidance and identify the supported fix or mitigation.
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Treatment intelligence
Remediation intelligence
Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.
Technical details
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CWE
- CWE-918
- Affected versions
- Tenable Terrascan (End Including 1.18.3)
- Fixed versions
- No explicit fixed version is currently recorded.
- Published
- 19 May 2026
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
Signal timeline
- CVE published
- Latest EPSS score: 0.5%
- Signal calculated at 13