CVE-2026-45366

MEDIUM

typescript-utcp: SSRF via attacker-controlled OpenAPI servers[0].url in HTTP communication protocol

Title source: cna
STIX 2.1

Description

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.

References (1)

Core 1

Scores

CVSS v3 4.7
EPSS 0.0012
EPSS Percentile 2.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-918
Status published
Products (2)
universal-tool-calling-protocol/typescript-utcp < 1.1.2
utcp/http 0 - 1.1.2npm
Published May 28, 2026
Tracked Since May 29, 2026