CVE-2026-90474 json
MCPHub before 1.0.32 OAuth 2.0 Authentication Bypass
published 2mo ago modified last mo. also EUVD-2026-76850 , GHSA-3m7m-37xf-xp9x
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository samanhappy/mcphub. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 6.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- samanhappy mcphub 1.0.32
Is CVE-2026-90474 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- last mo.
Exploit prediction
0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/samanhappy/mcphub/security/advisories/GHSA-3m7m-37xf-xp9x referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.6 | 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 |
| CNA | 3.1 | 6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| CNA | 4.0 | 7.6 | 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 |
Affected products
- samanhappy mcphub
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
github.com
/samanhappy/mcphub/commit/e927620cd1a80e8691213b01eb8cd6ffa1a66e9f
patch
-
github.com
/samanhappy/mcphub/security/advisories/GHSA-3m7m-37xf-xp9x
third-party-advisory, vendor-advisory, exploit, advisory
-
github.com
/samanhappy/mcphub/blob/v1.0.31/src/services/oauthServerService.ts#L26-L38
technical-description
-
github.com
/samanhappy/mcphub/releases/tag/v1.0.32
release-notes
-
vulncheck.com
/advisories/mcphub-before-1.0.32-oauth-2.0-authentication-bypass
third-party-advisory
Sources
- CVE List CVE-2026-90474
- NVD CVE-2026-90474
- Maintainer advisory GHSA-3m7m-37xf-xp9x
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of samanhappy/mcphub published their own advisory on GitHub. Reviewed sources take precedence over it.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.