CVE-2026-90474
MCPHub before 1.0.32 OAuth 2.0 Authentication Bypass
- State
- Published
- Severity
- 7.6 High
- Published
- Sep 12, 2026
- Updated
- Sep 24, 2026
- Reserved
- Sep 12, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.6 High | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 6.8 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-287 Improper Authentication
Affected Products
| Product | Versions |
|---|---|
mcphubsamanhappy |
|
References
- GitHub Security Advisory (GHSA-3m7m-37xf-xp9x)third-party-advisoryvendor-advisory
- fix(security): enforce OAuth client auth and S256-only PKCE policypatch
- getClient() verifies a registered secret only when one is supplied, at v1.0.31technical-description
- mcphub v1.0.32 Release Notesrelease-notes
- VulnCheck Advisory: MCPHub before 1.0.32 OAuth 2.0 Authentication Bypassthird-party-advisory
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