CVE-2026-90474

high

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.

References

https://www.vulncheck.com/advisories/mcphub-before-1.0.32-oauth-2.0-authentication-bypass

https://github.com/samanhappy/mcphub/security/advisories/GHSA-3m7m-37xf-xp9x

https://github.com/samanhappy/mcphub/releases/tag/v1.0.32

https://github.com/samanhappy/mcphub/commit/e927620cd1a80e8691213b01eb8cd6ffa1a66e9f

https://github.com/samanhappy/mcphub/blob/v1.0.31/src/services/oauthServerService.ts#L26-L38

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-76850

Details

Source: Mitre, NVD

Published: 2026-09-12

Updated: 2026-09-23

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 6.8

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Severity: Medium

CVSS v4

Base Score: 7.6

Vector: 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

Severity: High

EPSS

EPSS: 0.00553