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Fencer Intel
critical 9.9

CVE-2026-79748 json

MCPHub: Authenticated non-admin user achieves RCE via POST /api/servers (missing authorization on stdio command/args)

published 2mo ago modified 2mo ago also EUVD-2026-68686 , GHSA-mx89-jjx9-gjr8

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
9.9
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 50%
public exploits
0
none known

Summary

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 0.12.15, the POST /api/servers and PUT /api/servers/:name endpoints in MCPHub create/update MCP server configurations and then immediately spawn the configured stdio process via child_process.spawn. Authentication is required, but there is no authorization check restricting these endpoints to admins, and there is no allowlist/sanitization on the command and args fields. As a result, any authenticated non-admin user can submit a server configuration with command:"/bin/sh" (or any other binary) and arbitrary args, causing MCPHub to execute the attacker-controlled process as the MCPHub server's OS user (commonly root in the published Docker image and in npx/systemd deployments). This issue has been patched in version 0.12.15.

Patch / fix

  • mcphubx mcphub 0.12.15

Is CVE-2026-79748 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.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.64% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/samanhappy/mcphub/security/advisories/GHSA-mx89-jjx9-gjr8 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • samanhappy mcphub

Classification

Weakness

References

Sources

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.