CVE-2026-16498Network attack vector

Cross-tenant tool execution via sessionless client cache

Published Jul 28, 2026 · Updated Jul 28, 2026

Credential isolation failure in HashiCorp Terraform MCP Server 0.3.0 through 1.0.0 allows remote attackers to reuse another tenant's token. The stateless Streamable HTTP library supplies no unique session identifier, so the server's per-session Terraform client cache cannot separate request credentials and reuses the first cached client. Exploitation requires an explicitly configured stateless HTTP deployment; subsequent tool calls run with the earlier tenant's Terraform permissions.

CVSS severity10.0
Critical
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential isolation failure in HashiCorp Terraform MCP Server 0.3.0 through 1.0.0 allows remote attackers to reuse another tenant's token. The stateless Streamable HTTP library supplies no unique session identifier, so the server's per-session Terraform client cache cannot separate request credentials and reuses the first cached client. Exploitation requires an explicitly configured stateless HTTP deployment; subsequent tool calls run with the earlier tenant's Terraform permissions.

The record

CVE
CVE-2026-16498
Published
Jul 28, 2026
Updated
Jul 28, 2026
Vendor
HashiCorp
Product
Terraform MCP Server
Classifications
CWE-488, CAPEC-60, T1078.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.3.0 <1.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HashiCorp · Terraform MCP Serverversion=0.3.0 <1.1.0

Published CVSS scores

10.0HashiCorpCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-488Exposure of Data Element to Wrong Session
CAPEC-60Reusing Session IDs (Session Replay)
T1078.004Cloud Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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