{"id":"CVE-2026-81099","summary":"Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List","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.","modified":"2026-10-08T02:52:05.188347076Z","published":"2026-08-27T14:50:39.029Z","database_specific":{"cwe_ids":["CWE-346"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81099.json","cna_assigner":"VulnCheck"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/timescale/tiger-slack","events":[{"introduced":"0"},{"fixed":"23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09"}]}],"versions":["v0.2.6","v0.2.5","v0.2.4","v0.2.3","v0.2.2","v0.2.1","v0.2.0","v0.1.3","v0.1.2","v0.1.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81099.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","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"}]}