{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09"
            }
          ],
          "repo": "https://github.com/timescale/tiger-slack",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-346"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81099.json"
  },
  "details": "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.",
  "id": "CVE-2026-81099",
  "modified": "2026-10-08T02:30:21.087442970Z",
  "published": "2026-08-27T14:50:39.029Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81099.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81099"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/timescale-tiger-slack-dns-rebinding-via-disabled-host-header-allow-list"
    },
    {
      "type": "FIX",
      "url": "https://github.com/timescale/tiger-slack/pull/146"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/timescale/tiger-slack"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List"
}