Vulnerability · Published Aug 27, 2026 · Assigned by VulnCheck

CVE-2026-81100Timescale tiger-gh-mcp-server DNS Rebinding via Disabled Host Header Allow-List

Medium 6.8

In plain English

A medium-severity security flaw in tiger-gh-mcp-server from timescale. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.2%top 87.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
timescale	tiger-gh-mcp-server	0 – before e559b57b57cf61277525ec96bbf1edcf01b16a21

Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

References

https://github.com/timescale/tiger-gh-mcp-server product
https://github.com/timescale/tiger-gh-mcp-server/pull/36 issue-tracking, patch
VulnCheck Advisory: Timescale tiger-gh-mcp-server DNS Rebinding via Disabled Host Header Allow-List third-party-advisory