terraform-mcp-server vulnerable to cross-user credential inheritance if an MCP session ID is obtained by another user

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-16496
StatePUBLISHED
AssignerHashiCorp
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-28 19:17:31 UTC
Updated2026-07-28 19:17:31 UTC
DescriptionThe terraform-mcp-server before version 1.1.0 is vulnerable to an authorization bypass in the streamable-HTTP stateful transport mode that may allow a user who obtains another user's MCP session ID to have their tool calls executed using that user's Terraform credentials. This vulnerability, CVE-2026-16496, is fixed in terraform-mcp-server 1.1.0.

Risk And Classification

Primary CVSS: v3.1 8.9 HIGH from [email protected]

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

Problem Types: CWE-384 | CWE-384 CWE-384: Session Fixation

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.9HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L
3.1CNACVSS8.9HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA HashiCorp Tooling affected 0.3.0 1.1.0 semver 64 bit, 32 bit, x86, ARM, MacOS, Windows, Linux

References

ReferenceSourceLinkTags
discuss.hashicorp.com/t/hcsec-2026-23-multiple-vulnerabilities-impacting-hashicorp-... [email protected] discuss.hashicorp.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: This issue was reported to HashiCorp by Juan Pablo Martinez Kuhn of Coinspect. (en)

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