Vulnerability-Lookup

FKIE_CVE-2026-81098

Vulnerability from fkie_nvd - Published: 2026-08-27 17:20 - Updated: 2026-08-27 20:18

Severity

9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

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 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.

References

	URL	Tags
	disclosure@vulncheck.com	https://github.com/team-telnyx/telnyx-node
	disclosure@vulncheck.com	https://github.com/team-telnyx/telnyx-node/pull/450
	disclosure@vulncheck.com	https://github.com/team-telnyx/telnyx-node/security/advisories/GHSA-46jp-xr2h-fw7h
	disclosure@vulncheck.com	https://www.vulncheck.com/advisories/telnyx-mcp-server-through-6.83.0-missing-authentication-on-streamable-http-transport

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://github.com/team-telnyx/telnyx-node",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/telnyx-mcp",
          "product": "telnyx-mcp",
          "repo": "https://github.com/team-telnyx/telnyx-node",
          "vendor": "team-telnyx",
          "versions": [
            {
              "lessThanOrEqual": "6.83.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s 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\u0027s 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."
    }
  ],
  "id": "CVE-2026-81098",
  "lastModified": "2026-08-27T20:18:49.697",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-81098",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-27T18:47:34.829150Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-27T17:20:52.297",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/team-telnyx/telnyx-node"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/team-telnyx/telnyx-node/pull/450"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/team-telnyx/telnyx-node/security/advisories/GHSA-46jp-xr2h-fw7h"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://www.vulncheck.com/advisories/telnyx-mcp-server-through-6.83.0-missing-authentication-on-streamable-http-transport"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Secondary"
    }
  ]
}

CVE-2026-81098 (GCVE-0-2026-81098)

Vulnerability from cvelistv5 – Published: 2026-08-27 14:50 – Updated: 2026-08-29 11:48

Title

Telnyx MCP Server through 6.83.0 Missing Authentication on Streamable HTTP Transport

Summary

Severity

9.3 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

9.1 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-27 18:47 UTC

CWE

CWE-306 - Missing Authentication for Critical Function

Assigner

VulnCheck mitre root

References

4 references

URL	Tags
https://github.com/team-telnyx/telnyx-node	product
https://github.com/team-telnyx/telnyx-node/pull/450	issue-trackingpatch
https://github.com/team-telnyx/telnyx-node/securi…	vendor-advisory
https://www.vulncheck.com/advisories/telnyx-mcp-s…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
team-telnyx	telnyx-mcp	Affected: 0 , ≤ 6.83.0 (semver)

Date Public

2026-08-26 00:00

Credits

Avishai Gonen (Pluto Security)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-81098",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-27T18:47:34.829150Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-27T18:47:58.070Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com/team-telnyx/telnyx-node",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/telnyx-mcp",
          "product": "telnyx-mcp",
          "repo": "https://github.com/team-telnyx/telnyx-node",
          "vendor": "team-telnyx",
          "versions": [
            {
              "lessThanOrEqual": "6.83.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Avishai Gonen (Pluto Security)"
        }
      ],
      "datePublic": "2026-08-26T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s 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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-306",
              "description": "Missing Authentication for Critical Function",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-29T11:48:12.176Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/team-telnyx/telnyx-node"
        },
        {
          "tags": [
            "issue-tracking",
            "patch"
          ],
          "url": "https://github.com/team-telnyx/telnyx-node/pull/450"
        },
        {
          "name": "GitHub Security Advisory (GHSA-46jp-xr2h-fw7h)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/team-telnyx/telnyx-node/security/advisories/GHSA-46jp-xr2h-fw7h"
        },
        {
          "name": "VulnCheck Advisory: Telnyx MCP Server through 6.83.0 Missing Authentication on Streamable HTTP Transport",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/telnyx-mcp-server-through-6.83.0-missing-authentication-on-streamable-http-transport"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Telnyx MCP Server through 6.83.0 Missing Authentication on Streamable HTTP Transport",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-81098",
    "datePublished": "2026-08-27T14:50:38.327Z",
    "dateReserved": "2026-08-26T16:00:33.062Z",
    "dateUpdated": "2026-08-29T11:48:12.176Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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FKIE_CVE-2026-81098

CVE-2026-81098 (GCVE-0-2026-81098)

Tags

Sightings

Nomenclature

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