CVE-2026-16326Network attack vector

Cross-tenant tool execution via cached authenticated client

Published Jul 29, 2026 · Updated Jul 29, 2026

Session isolation failure in HashiCorp Consul MCP Server 0.1.0 through 0.1.3 allows remote attackers to execute tools with another client's token. In StreamableHTTP stateless mode, the per-session cache reuses an authenticated Consul client while handling a different client, carrying the cached token into the later request. Exposure requires stateless mode and multiple connected clients; stateful deployments are unaffected, and resulting access is limited by the reused token's Consul permissions.

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

What happened

Session isolation failure in HashiCorp Consul MCP Server 0.1.0 through 0.1.3 allows remote attackers to execute tools with another client's token. In StreamableHTTP stateless mode, the per-session cache reuses an authenticated Consul client while handling a different client, carrying the cached token into the later request. Exposure requires stateless mode and multiple connected clients; stateful deployments are unaffected, and resulting access is limited by the reused token's Consul permissions.

The record

CVE
CVE-2026-16326
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
HashiCorp
Product
Consul MCP Server
Classifications
CWE-488, T1550
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 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=0.1.0 <0.1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HashiCorp · Consul MCP Serverversion=0.1.0 <0.1.4

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.

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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
T1550Use Alternate Authentication Material

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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