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CVE-2026-90474
MCPHub before 1.0.32 OAuth 2.0 Authentication Bypass
High7.6EPSS 0.55%
- Published
- Updated
- Reserved
- Assigned by
- VulnCheck
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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | High7.6 | 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 |
| VulnCheckCNA (assigner) | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| NVDNVD · Deferred | 4.0 | High7.6 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.55% · top 54% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.6.
Weakness
Affected products
- affected < 1.0.32
References (5)
- GitHub Security Advisory (GHSA-3m7m-37xf-xp9x) (opens in a new tab)third-party-advisoryvendor-advisoryexploit
- fix(security): enforce OAuth client auth and S256-only PKCE policy (opens in a new tab)patch
- getClient() verifies a registered secret only when one is supplied, at v1.0.31 (opens in a new tab)technical-description
- mcphub v1.0.32 Release Notes (opens in a new tab)release-notes
- VulnCheck Advisory: MCPHub before 1.0.32 OAuth 2.0 Authentication Bypass (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-90474)Record last updated .