{"id":"CVE-2026-81098","title":"The Telnyx MCP server exposed its HTTP transport on every interface and did not require a caller credential","summary":"The Telnyx MCP server exposed its HTTP transport on every interface and did not require a caller credential. packages/mcp-server/src/http.ts served MCP on the root path with a listener bound to all interfaces and parsed the caller's auth…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-306"],"published":"2026-08-27","updated":"2026-09-24","sourceUpdated":"2026-09-24T20:43:32.537","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81098","references":[{"url":"https://github.com/team-telnyx/telnyx-node","label":"disclosure@vulncheck.com"},{"url":"https://github.com/team-telnyx/telnyx-node/pull/450","label":"disclosure@vulncheck.com"},{"url":"https://github.com/team-telnyx/telnyx-node/security/advisories/GHSA-46jp-xr2h-fw7h","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/telnyx-mcp-server-through-6.83.0-missing-authentication-on-streamable-http-transport","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"epss":0.00727,"epssPercentile":0.52123,"ingestedAt":"2026-09-24T20:51:40.235Z","slug":"CVE-2026-81098","body":"## Overview\n\nThe Telnyx MCP server exposed its HTTP transport on every interface and did not require a caller credential. packages/mcp-server/src/http.ts served MCP on the root path with a listener bound to all interfaces and parsed the caller's authentication headers in a mode that did not fail when they were absent, so a request without any credential completed initialisation and dispatched tools. Dispatch forwarded the server's own stored credentials, the Telnyx API key and client secret together with the code-execution key, to the upstream endpoint, so an unauthenticated caller able to reach the port acted with them. The current code defaults the host to loopback, requires a server API key, and enforces it in middleware.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}