CVE-2026-81100

high

Description

tiger-gh-mcp-server 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, making the locally reachable GitHub MCP endpoint drivable from a page in a visitor's browser that pointed a name it controlled at the bound address. The fix passes the option explicitly alongside a dependency update; the update alone would not have closed it. The repository has published no release that brackets the fix, so the affected boundary is the commit preceding it.

References

https://www.vulncheck.com/advisories/timescale-tiger-gh-mcp-server-dns-rebinding-via-disabled-host-header-allow-list

https://github.com/timescale/tiger-gh-mcp-server/pull/36

https://github.com/timescale/tiger-gh-mcp-server

Details

Source: Mitre, NVD

Published: 2026-08-27

Updated: 2026-08-29

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: 0.0016