{"id":"CVE-2026-81099","state":"PUBLISHED","title":"Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List","description":"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.","publishedAt":"2026-08-27T14:50:39.029Z","updatedAt":"2026-08-29T11:48:12.861Z","severity":{"score":7.6,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["timescale tiger-slack"],"affected":[{"vendor":"timescale","product":"tiger-slack","defaultStatus":"unaffected","versions":[{"version":"23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09","status":"unaffected","versionType":"git"},{"version":"0","status":"affected","lessThan":"23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09","versionType":"git"}],"collectionURL":"https://github.com/timescale/tiger-slack","repo":"https://github.com/timescale/tiger-slack"}],"references":["https://github.com/timescale/tiger-slack","https://github.com/timescale/tiger-slack/pull/146","https://www.vulncheck.com/advisories/timescale-tiger-slack-dns-rebinding-via-disabled-host-header-allow-list"],"weaknesses":["CWE-346"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/81xxx/CVE-2026-81099.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-81099","state":"PUBLISHED","datePublished":"2026-08-27T14:50:39.029Z","dateUpdated":"2026-08-29T11:48:12.861Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-08-26T16:00:33.425Z"},"containers":{"cna":{"title":"Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"timescale","product":"tiger-slack","defaultStatus":"unaffected","versions":[{"version":"23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09","status":"unaffected","versionType":"git"},{"version":"0","status":"affected","lessThan":"23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09","versionType":"git"}],"collectionURL":"https://github.com/timescale/tiger-slack","repo":"https://github.com/timescale/tiger-slack"}],"references":[{"url":"https://github.com/timescale/tiger-slack","tags":["product"]},{"url":"https://github.com/timescale/tiger-slack/pull/146","tags":["issue-tracking","patch"]},{"url":"https://www.vulncheck.com/advisories/timescale-tiger-slack-dns-rebinding-via-disabled-host-header-allow-list","name":"VulnCheck Advisory: Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.6,"vectorString":"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"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","version":"3.1","baseSeverity":"MEDIUM","baseScore":6.8,"vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-346","lang":"en","description":"Origin Validation Error","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-29T11:48:12.861Z"},"datePublic":"2026-08-26T00:00:00.000Z","credits":[{"lang":"en","value":"Avishai Gonen (Pluto Security)","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"},"source":{"discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-27T17:53:13.312915Z","id":"CVE-2026-81099","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-27T17:53:20.090Z"}}]}}}