Blind SSRF in python-utcp Prior to Version 1.1.3
CVE-2026-44661

4.7MEDIUM

Key Information:

Vendor

Universal-tool-calling-protocol

Status
Python-utcp
Vendor
CVE Published:
14 May 2026

What is CVE-2026-44661?

The python-utcp implementation is affected by a blind Server-Side Request Forgery (SSRF) due to a vulnerability within the utcp-http plugin prior to version 1.1.3. This flaw arises from an inconsistency in the trust boundary during manual discovery and tool invocation. Specifically, while register_manual() properly validates the discovery URL against an HTTPS and loopback allowlist, the call_tool() and call_tool_streaming() functions fail to revalidate the resolved tool_call_template.url, instead using it directly. Consequently, an attacker can maliciously craft a specification hosted on a legitimate HTTPS endpoint that points to internal services, potentially exposing sensitive information and creating security risks. The vulnerability affects all three HTTP-class protocols within the utcp_http framework.

Affected Version(s)

python-utcp < 1.1.2

References

https://github.com/universal-tool-calling-protocol/python...
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

.