CVE-2026-90474 Details
Description
MCPHub before 1.0.32 contains an authentication bypass vulnerability in its embedded OAuth 2.0 authorization server where client authentication is disabled by default and PKCE enforcement is optional. Attackers who obtain an authorization code through interception can redeem it for access tokens without providing a client secret or PKCE verifier, gaining access to victim accounts and their privileges.
An authentication bypass vulnerability has been identified in MCPHub versions prior to 1.0.32. The issue resides in the embedded OAuth 2.0 authorization server, where client authentication is disabled by default and PKCE enforcement is optional. This allows attackers to intercept authorization codes and redeem them for access tokens without needing a client secret or PKCE verifier, thereby gaining access to the accounts and privileges of the affected users.
Users can update to MCPHub version 1.0.32 or later, where this vulnerability has been addressed. Instructions for updating can be found in the release notes on the MCPHub GitHub repository.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 12, 2026CISA-ADP
Assessed Sep 15, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-287 | Improper Authentication | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| MCPHub | <= 1.0.31 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 15, 2026 | CVE Modified | CISA-ADP |
| Sep 12, 2026 | New CVE Received | [email protected] |