CVE-2026-90474Network attack vectorHinoki check available

Account access via secretless authorization-code redemption

Published Sep 12, 2026 · Updated Sep 12, 2026

Authentication bypass in MCPHub before 1.0.32 allows remote attackers with intercepted authorization codes to obtain access tokens. The token endpoint accepted confidential clients without validating their registered secret, while public clients could complete authorization without an S256 PKCE challenge and verifier. Exploitation requires interception of a victim authorization code; redeeming it grants access to that account and its existing privileges.

CVSS severityUnavailable
Unscored
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authentication bypass in MCPHub before 1.0.32 allows remote attackers with intercepted authorization codes to obtain access tokens. The token endpoint accepted confidential clients without validating their registered secret, while public clients could complete authorization without an S256 PKCE challenge and verifier. Exploitation requires interception of a victim authorization code; redeeming it grants access to that account and its existing privileges.

The record

CVE
CVE-2026-90474
Published
Sep 12, 2026
Updated
Sep 12, 2026
Vendor
MCPHub
Product
MCPHub
Classifications
T1528
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 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 <1.0.32

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MCPHub · MCPHubversion=0 <1.0.32

Published CVSS scores

No CVSS assessment is available in this record.

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

T1528Steal Application Access Token

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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