Blind Server-Side Request Forgery Vulnerability in UTCP by Universal Tool Calling Protocol
CVE-2026-45366

4.7MEDIUM

Key Information:

Vendor

Universal-tool-calling-protocol

Status
Typescript-utcp
Vendor
CVE Published:
28 May 2026

What is CVE-2026-45366?

The typescript-utcp package, prior to version 1.1.2, is susceptible to a blind Server-Side Request Forgery (SSRF). This flaw stems from a trust-boundary inconsistency where the registerManual() function checks discovery URLs against an HTTPS and loopback allowlist, but the callTool() function fails to revalidate URLs derived from toolCallTemplate.url. Consequently, an attacker could exploit a malicious OpenAPI specification, leading to unauthorized access to internal services by instructing the converter to produce tools that point to sensitive URLs such as http://127.0.0.1:9090 or http://169.254.169.254. This vulnerability was resolved in version 1.1.2.

Affected Version(s)

typescript-utcp < 1.1.2

References

https://github.com/universal-tool-calling-protocol/typesc...
x_refsource_CONFIRM

CVSS V3.1

Score:
4.7
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.