9.3

CVE-2026-81098: team-telnyx telnyx-mcp

CVSS: 9.3v4.0CriticalDeferred
Published 27-08-2026Last modified 29-08-2026
Open JSON

Vulnerability summary

CVE-2026-81098 is a critical (CVSS 9.3) vulnerability in team-telnyx telnyx-mcp. EPSS estimates a 0.73% chance of exploitation in the next 30 days, higher than 53.5% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.3/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.73%
0%100%
Low · +0.22 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 27-08-2026
    PublishedVulnerability first disclosed.
  2. 29-08-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.73%

Chance of exploitation in the next 30 days

Percentile

54%

Versus all other CVEs

30-day change

+0.22 pp

From 0.51% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.73%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Team-telnyx1 product

1 vendor · 1 product

References

4 links