CVE-2026-129094
@utcp/http before 1.1.14 SSRF to Loopback via Host Placeholder in Call Templates
CVSS Score
4.7
EPSS Score
0.0%
EPSS Percentile
0th
@utcp/http before 1.1.14 contains a server-side request forgery vulnerability that allows remote manuals to reach loopback services by bypassing the remote-loopback check with a {host} placeholder. Attackers can supply host arguments like 127.0.0.1 or register tools via Streamable HTTP and SSE discovery to access internal services on the agent machine.
| CWE | CWE-918 |
| Vendor | universal-tool-calling-protocol |
| Product | @utcp/http |
| Published | Nov 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
universal-tool-calling-protocol / @utcp/http
0 < 1.1.14
References
github.com: https://github.com/universal-tool-calling-protocol/typescript-utcp/pull/58 github.com: https://github.com/universal-tool-calling-protocol/typescript-utcp/pull/60 github.com: https://github.com/universal-tool-calling-protocol/typescript-utcp/security/advisories/GHSA-r8j5-8747-88cm npmjs.com: https://www.npmjs.com/package/@utcp/http vulncheck.com: https://www.vulncheck.com/advisories/utcp-http-before-1.1.14-ssrf-to-loopback-via-host-placeholder-in-call-templates
Credits
Zachariah Mithani (AploSec)