CVE-2026-81098

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-27. the CNA's CVSS baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.1
EG Score
9.1(high)
EG Risk
56(Track)
EG Risk 56/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
42%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 29, 2026

Advisory Details (3)

Auto-updated Sep 15, 2026
Patch available. Sources: github_pr.
generic

Telnyx MCP Server through 6.83.0 Missing Authentication on Streamable HTTP Transport | Advisories | VulnCheck

https://www.vulncheck.com/advisories/telnyx-mcp-server-through-6.83.0-missing-authentication-on-streamable-http-transport
github_pr Patch Available

fix: restore MCP server source files from v6.83.0

Patch available: team-telnyx/telnyx-node v7.2.0 (PR #450 merged 2026-06-24)

https://github.com/team-telnyx/telnyx-node/pull/450
generic

GitHub - team-telnyx/telnyx-node: Node SDK for the Telnyx API · GitHub

https://github.com/team-telnyx/telnyx-node

Vendor Advisories for CVE-2026-81098(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 56× in last 7d / 205× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 205 total refreshes for this CVE.

  1. 2026-09-21 06:46 UTCGHSA enrichment
  2. 2026-09-21 03:07 UTCGHSA enrichment
  3. 2026-09-20 23:22 UTCEG score recompute
  4. 2026-09-20 23:22 UTCGHSA enrichment
  5. 2026-09-20 20:16 UTCEPSS rescore
  6. 2026-09-20 19:18 UTCGHSA enrichment
  7. 2026-09-20 15:40 UTCGHSA enrichment
  8. 2026-09-20 12:00 UTCGHSA enrichment
  9. 2026-09-20 08:20 UTCGHSA enrichment
  10. 2026-09-20 04:15 UTCGHSA enrichment
  11. 2026-09-20 00:37 UTCGHSA enrichment
  12. 2026-09-19 20:58 UTCGHSA enrichment
  13. 2026-09-19 17:19 UTCEG score recompute
  14. 2026-09-19 17:19 UTCGHSA enrichment
  15. 2026-09-19 13:40 UTCGHSA enrichment
  16. 2026-09-19 10:02 UTCGHSA enrichment
  17. 2026-09-19 05:44 UTCGHSA enrichment
  18. 2026-09-19 02:06 UTCGHSA enrichment
  19. 2026-09-18 22:27 UTCEG score recompute
  20. 2026-09-18 22:27 UTCGHSA enrichment
  21. 2026-09-18 19:28 UTCEPSS rescore
  22. 2026-09-18 18:49 UTCGHSA enrichment
  23. 2026-09-18 15:10 UTCGHSA enrichment
  24. 2026-09-18 11:30 UTCGHSA enrichment
  25. 2026-09-18 07:51 UTCGHSA enrichment
Show 75 more
  1. 2026-09-18 04:13 UTCGHSA enrichment
  2. 2026-09-18 00:34 UTCGHSA enrichment
  3. 2026-09-17 20:55 UTCEG score recompute
  4. 2026-09-17 20:55 UTCGHSA enrichment
  5. 2026-09-17 14:21 UTCGHSA enrichment
  6. 2026-09-17 10:29 UTCGHSA enrichment
  7. 2026-09-17 06:50 UTCGHSA enrichment
  8. 2026-09-17 03:11 UTCGHSA enrichment
  9. 2026-09-16 22:43 UTCGHSA enrichment
  10. 2026-09-16 19:04 UTCEG score recompute
  11. 2026-09-16 19:04 UTCGHSA enrichment
  12. 2026-09-16 14:08 UTCEPSS rescore
  13. 2026-09-16 12:54 UTCGHSA enrichment
  14. 2026-09-16 09:15 UTCEG score recompute
  15. 2026-09-16 09:15 UTCGHSA enrichment
  16. 2026-09-16 05:15 UTCEPSS rescore
  17. 2026-09-16 04:33 UTCGHSA enrichment
  18. 2026-09-16 00:45 UTCGHSA enrichment
  19. 2026-09-15 20:57 UTCGHSA enrichment
  20. 2026-09-15 16:46 UTCGHSA enrichment
  21. 2026-09-15 13:08 UTCGHSA enrichment
  22. 2026-09-15 09:29 UTCGHSA enrichment
  23. 2026-09-15 05:50 UTCEG score recompute
  24. 2026-09-15 05:50 UTCGHSA enrichment
  25. 2026-09-15 03:12 UTCEPSS rescore
  26. 2026-09-15 03:12 UTCEPSS rescore
  27. 2026-09-15 02:12 UTCGHSA enrichment
  28. 2026-09-14 22:27 UTCGHSA enrichment
  29. 2026-09-14 18:48 UTCGHSA enrichment
  30. 2026-09-14 14:52 UTCGHSA enrichment
  31. 2026-09-14 11:13 UTCGHSA enrichment
  32. 2026-09-14 07:35 UTCGHSA enrichment
  33. 2026-09-14 03:56 UTCGHSA enrichment
  34. 2026-09-14 00:18 UTCGHSA enrichment
  35. 2026-09-13 20:39 UTCGHSA enrichment
  36. 2026-09-13 17:00 UTCEG score recompute
  37. 2026-09-13 17:00 UTCGHSA enrichment
  38. 2026-09-13 13:21 UTCGHSA enrichment
  39. 2026-09-13 09:42 UTCGHSA enrichment
  40. 2026-09-13 06:03 UTCGHSA enrichment
  41. 2026-09-13 02:24 UTCGHSA enrichment
  42. 2026-09-12 22:45 UTCGHSA enrichment
  43. 2026-09-12 19:06 UTCGHSA enrichment
  44. 2026-09-12 15:27 UTCEG score recompute
  45. 2026-09-12 15:27 UTCGHSA enrichment
  46. 2026-09-12 11:46 UTCGHSA enrichment
  47. 2026-09-12 08:05 UTCGHSA enrichment
  48. 2026-09-12 04:26 UTCGHSA enrichment
  49. 2026-09-12 00:47 UTCGHSA enrichment
  50. 2026-09-11 21:08 UTCGHSA enrichment
  51. 2026-09-11 17:29 UTCEG score recompute
  52. 2026-09-11 17:29 UTCGHSA enrichment
  53. 2026-09-11 14:53 UTCEPSS rescore
  54. 2026-09-11 14:53 UTCEPSS rescore
  55. 2026-09-11 13:33 UTCGHSA enrichment
  56. 2026-09-11 09:53 UTCEG score recompute
  57. 2026-09-11 09:53 UTCGHSA enrichment
  58. 2026-09-11 06:12 UTCGHSA enrichment
  59. 2026-09-11 02:33 UTCGHSA enrichment
  60. 2026-09-10 22:54 UTCGHSA enrichment
  61. 2026-09-10 19:15 UTCGHSA enrichment
  62. 2026-09-10 15:35 UTCGHSA enrichment
  63. 2026-09-10 11:52 UTCEG score recompute
  64. 2026-09-10 11:52 UTCGHSA enrichment
  65. 2026-09-10 07:19 UTCGHSA enrichment
  66. 2026-09-10 03:40 UTCGHSA enrichment
  67. 2026-09-10 00:00 UTCGHSA enrichment
  68. 2026-09-09 18:54 UTCGHSA enrichment
  69. 2026-09-09 15:16 UTCGHSA enrichment
  70. 2026-09-09 11:37 UTCGHSA enrichment
  71. 2026-09-09 07:58 UTCGHSA enrichment
  72. 2026-09-09 04:20 UTCGHSA enrichment
  73. 2026-09-09 00:41 UTCEG score recompute
  74. 2026-09-09 00:41 UTCGHSA enrichment
  75. 2026-09-08 22:01 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81098?
CVE-2026-81098 is a critical vulnerability published on August 27, 2026. 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…
When was CVE-2026-81098 disclosed?
CVE-2026-81098 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81098 actively exploited?
CVE-2026-81098 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.9% of all scored CVEs.
What is the CVSS score of CVE-2026-81098?
CVE-2026-81098 has a CVSS v4.0 base score of 9.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-81098?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81098, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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