High severity · published Aug 31, 2026
CVE-2026-79746
MCPHub: Server-scoped bearer key gains access to an entire group via partial (any-overlap) server matching
8.1
CVSS
0.4%
EPSS
No
On KEV
Description
MCPHub is a unified hub for centrally managing and dynamically orchestrating multiple MCP servers/APIs into separate endpoints with flexible routing strategies. Prior to version 1.0.31, when a bearer key with accessType: 'servers' (or 'custom') is used against a group route, isBearerKeyAllowedForRequest grants access to the entire group as long as any single server in that group appears in the key's allowedServers list — not only when every server the key is scoped to matches, and critically, without ever re-checking allowedServers again once the group-level connection is authorized. A key explicitly scoped to one specific server therefore also grants full access to every other server that happens to share a group with it, including servers the key was never authorized for. This issue has been patched in version 1.0.31.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
mcphub · samanhappy
< 1.0.31 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-79746
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-79746
github.com
https://github.com/samanhappy/mcphub/commit/2b10ae36112ce68deebf910b22505d44efcef552
github.com
https://github.com/samanhappy/mcphub/pull/1059
github.com
https://github.com/samanhappy/mcphub/releases/tag/v1.0.31
github.com
https://github.com/samanhappy/mcphub/security/advisories/GHSA-454m-4vm6-842f
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