CVE-2026-58446Public exploitNetwork attack vector

Unauthenticated MCP tool access via token injection

Published Jun 30, 2026 · Updated Jun 30, 2026

Authentication bypass in Presenton before 0.8.8-beta allows remote attackers to invoke MCP tools through an unprotected server endpoint. The nginx front end omits auth_request on /mcp, while the MCP server creates and injects a valid session token into forwarded API calls. Exposure requires a server or Docker deployment with AUTH_USERNAME and AUTH_PASSWORD; attackers can create presentations and consume configured LLM API quota.

CVSS severity6.9
Medium
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Presenton before 0.8.8-beta allows remote attackers to invoke MCP tools through an unprotected server endpoint. The nginx front end omits auth_request on /mcp, while the MCP server creates and injects a valid session token into forwarded API calls. Exposure requires a server or Docker deployment with AUTH_USERNAME and AUTH_PASSWORD; attackers can create presentations and consume configured LLM API quota.

The record

CVE
CVE-2026-58446
Published
Jun 30, 2026
Updated
Jun 30, 2026
Vendor
Presenton Inc.
Product
Presenton
Classifications
CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 30, 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 <0.8.8-beta

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Presenton Inc. · Presentonversion=0 <0.8.8-beta

Published CVSS scores

6.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
6.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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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