Timescale tiger-gh-mcp-server DNS Rebinding via Disabled Host Header Allow-List (CVE-2026-81100) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-81100

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

Answer in brief

CVE-2026-81100 records a Unknown severity vulnerability in Timescale tiger-gh-mcp-server DNS Rebinding via Disabled Host Header Allow-List. The current sources do not mark it as known exploited. The current feed maps timescale/tiger-gh-mcp-server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 27, 2026Updated Aug 27, 2026Source checked Aug 27, 2026First seen by HOL Aug 27, 2026Material review Aug 27, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps timescale/tiger-gh-mcp-server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
timescale/tiger-gh-mcp-servergeneric	>=0 <e559b57b57cf61277525ec96bbf1edcf01b16a21	e559b57b57cf61277525ec96bbf1edcf01b16a21

Recommended response

Check inventory. Check lockfiles and deployed manifests for timescale/tiger-gh-mcp-server.
Review the reported fix. Update timescale/tiger-gh-mcp-server to e559b57b57cf61277525ec96bbf1edcf01b16a21 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 27, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.