MEDIUMVulnerability

CVE-2026-81099

tiger-slack started its MCP HTTP transport without enabling the host allow-list the underlying SDK provides. mcp/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, and a page in a browser could point a name it controlled at the address the server was bound to and drive the locally reachable Slack MCP server through the visitor's browser. The fix passes the option explicitly alongside a dependency update; the update alone would not have closed it. The repository publishes no release that brackets the fix, so the affected boundary is the commit preceding it.

Properties

severity
MEDIUM
score
6.8
cve_id
CVE-2026-81099
signal_observed_at
2026-09-23T22:44:39+00:00
vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
published_at
2026-08-27T17:20:52.467
last_modified
2026-09-23T17:17:42.577

Related Entities (2)

HAS_WEAKNESS (1)

[Weakness]Origin Validation Error

DESCRIBED_BY (1)

[Source]NVD

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CVE-2026-81099 — Ninja Signal Threat Intelligence | Ninja Signal