CVE-2026-50287Public exploitNetwork attack vectorHinoki check available

Unauthenticated administrative actions via unguarded MCP endpoint

Published Jun 12, 2026 · Updated Jun 12, 2026

Authentication bypass in AgenticMail @agenticmail/mcp before 0.9.27 allows remote attackers to invoke MCP tools through HTTP. The /mcp handler accepts initialization and tool-call requests without checking HTTP authorization, then forwards master-only operations with the server's configured master key. Exposure requires the optional --http or MCP_HTTP=1 mode and network reachability; default stdio mode is unaffected, while reachable clients gain administrative and gateway capabilities.

CVSS severity8.7
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authentication bypass in AgenticMail @agenticmail/mcp before 0.9.27 allows remote attackers to invoke MCP tools through HTTP. The /mcp handler accepts initialization and tool-call requests without checking HTTP authorization, then forwards master-only operations with the server's configured master key. Exposure requires the optional --http or MCP_HTTP=1 mode and network reachability; default stdio mode is unaffected, while reachable clients gain administrative and gateway capabilities.

The record

CVE
CVE-2026-50287
Published
Jun 12, 2026
Updated
Jun 12, 2026
Vendor
AgenticMail
Product
@agenticmail/mcp
Classifications
CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 12, 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=< 0.9.27

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

AgenticMail · @agenticmail/mcpversion=< 0.9.27

Published CVSS scores

8.7GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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 exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

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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