CVE-2026-79746 MCPHub: Server-scoped bearer key gains access to an entire group via partial (any-overlap) server matching
Attackers with a key scoped to one server can access all servers in the same group due to flawed authorization logic in MCPHub.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-79746?
CVE-2026-79746 is a high-severity missing authorization vulnerability in samanhappy mcphub, published on 31 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-863
Which versions are affected by CVE-2026-79746?
How do I fix CVE-2026-79746?
No fix has been published for CVE-2026-79746 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-79746 being exploited?
There is no known exploitation of CVE-2026-79746 in the wild and no public exploit code.
Sources
Also known as GHSA-454m-4vm6-842f.