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 — 4 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
41%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 29, 2026

Advisory Details (3)

Auto-updated Aug 29, 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 27× in last 7d / 27× 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.

  1. 2026-08-30 02:39 UTCEG score recompute
  2. 2026-08-30 02:39 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 23:00 UTCGHSA enrichment
  5. 2026-08-29 19:22 UTCGHSA enrichment
  6. 2026-08-29 15:39 UTCGHSA enrichment
  7. 2026-08-29 11:59 UTCEG score recompute
  8. 2026-08-29 11:59 UTCGHSA enrichment
  9. 2026-08-29 10:55 UTCGHSA enrichment
  10. 2026-08-29 07:13 UTCGHSA enrichment
  11. 2026-08-29 03:33 UTCGHSA enrichment
  12. 2026-08-28 23:54 UTCEG score recompute
  13. 2026-08-28 23:53 UTCGHSA enrichment
  14. 2026-08-28 21:42 UTCEPSS rescore
  15. 2026-08-28 18:26 UTCGHSA enrichment
  16. 2026-08-28 14:45 UTCGHSA enrichment
  17. 2026-08-28 11:02 UTCGHSA enrichment
  18. 2026-08-28 07:24 UTCGHSA enrichment
  19. 2026-08-28 03:45 UTCGHSA enrichment
  20. 2026-08-28 00:07 UTCGHSA enrichment
  21. 2026-08-27 20:27 UTCEG score recompute
  22. 2026-08-27 20:27 UTCGHSA enrichment
  23. 2026-08-27 20:18 UTCEG score recompute
  24. 2026-08-27 20:18 UTCGHSA enrichment
  25. 2026-08-27 17:27 UTCEG score recompute
Show 2 more
  1. 2026-08-27 16:47 UTCEG score recompute
  2. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

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 59.1% 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-81098

Explore →

Is Your Infrastructure Affected by CVE-2026-81098?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs