team-telnyx telnyx-mcp up to 6.83.0 HTTP Transport http.ts improper authentication

Summaryinfo

A vulnerability was found in team-telnyx telnyx-mcp up to 6.83.0 and classified as critical. The impacted element is an unknown function of the file packages/mcp-server/src/http.ts of the component HTTP Transport. Such manipulation leads to improper authentication. This vulnerability is referenced as CVE-2026-81098. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in team-telnyx telnyx-mcp up to 6.83.0. It has been rated as critical. Affected by this issue is an unknown code of the file packages/mcp-server/src/http.ts of the component HTTP Transport. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-81098 since 08/26/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/27/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Artificial Intelligence Software

Vendor

• team-telnyx

Name

• telnyx-mcp

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9
• 6.10
• 6.11
• 6.12
• 6.13
• 6.14
• 6.15
• 6.16
• 6.17
• 6.18
• 6.19
• 6.20
• 6.21
• 6.22
• 6.23
• 6.24
• 6.25
• 6.26
• 6.27
• 6.28
• 6.29
• 6.30
• 6.31
• 6.32
• 6.33
• 6.34
• 6.35
• 6.36
• 6.37
• 6.38
• 6.39
• 6.40
• 6.41
• 6.42
• 6.43
• 6.44
• 6.45
• 6.46
• 6.47
• 6.48
• 6.49
• 6.50
• 6.51
• 6.52
• 6.53
• 6.54
• 6.55
• 6.56
• 6.57
• 6.58
• 6.59
• 6.60
• 6.61
• 6.62
• 6.63
• 6.64
• 6.65
• 6.66
• 6.67
• 6.68
• 6.69
• 6.70
• 6.71
• 6.72
• 6.73
• 6.74
• 6.75
• 6.76
• 6.77
• 6.78
• 6.79
• 6.80
• 6.81
• 6.82
• 6.83.0

CPE 2.3info

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CPE 2.2info

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