universal-tool-calling-protocol typescript-utcp up to 1.1.1 registerManual server-side request forgery

Summaryinfo

A vulnerability was found in universal-tool-calling-protocol typescript-utcp up to 1.1.1 and classified as critical. This issue affects the function registerManual. The manipulation results in server-side request forgery. This vulnerability is known as CVE-2026-45366. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in universal-tool-calling-protocol typescript-utcp up to 1.1.1. Affected is the function registerManual. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

typescript-utcp is a typescript implementation of UTCP. Prior to 1.1.2, the @utcp/http package is vulnerable to a blind Server-Side Request Forgery (SSRF) caused by a trust-boundary inconsistency between manual discovery and tool invocation. registerManual() validates the discovery URL against an HTTPS / loopback allowlist, but callTool() reuses the resolved toolCallTemplate.url directly without revalidating, and the OpenApiConverter blindly trusts whatever servers[0].url an attacker-hosted spec declares. An attacker who hosts a malicious OpenAPI spec on a legitimate HTTPS endpoint can declare e.g. servers: [{ url: "http://127.0.0.1:9090" }] or servers: [{ url: "http://169.254.169.254" }]; the converter then produces tools whose URL points at internal services on the agent host. This vulnerability is fixed in 1.1.2.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-45366 since 05/12/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

Upgrading to version 1.1.2 eliminates this vulnerability.

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Productinfo

Vendor

• universal-tool-calling-protocol

Name

• typescript-utcp

Version

• 1.1.0
• 1.1.1

Website

• Product: https://github.com/universal-tool-calling-protocol/typescript-utcp/

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