6.8mediumMedium

CVE-2026-81095

pg-aiguide started its MCP HTTP transport without enabling the host allow-list the underlying SDK provides. src/httpServer.ts called the shared httpServerFactory helper and never set the DNS-rebinding-protection option, so the transport accepted a request whatever host it named. A page in a browser could therefore point a name it controlled at the address the server was bound to and drive the locally reachable MCP server through the visitor's browser. The protection was already available in the packaged transport and simply not turned on, so updating the dependency alone would not have closed it. Version 0.5.1 passes the option explicitly.

What the metrics mean

  • It is reachable over a network, without needing local access.
  • For an attacker who can reach it, exploitation depends on conditions outside the attacker's control.
  • To exploit it, no account is needed.
  • Beyond that, someone has to be persuaded to take an action first.

Scoring

CVSS
6.8 (v3.1)
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS v4
7.6
Weakness
CWE-346
Assigned by
disclosure@vulncheck.com

Dates

Published
2026-08-27
Last modified
2026-08-29
Sources
NVD

References