python-utcp before 1.1.12 SSRF via Remote HTTP Manual
python-utcp (pip package utcp-http) before 1.1.12 does not verify whether tool URLs declared in a hand-written UTCP manual point at the agent's own loopback interface when that manual is discovered from a remote, non-loopback origin. Because ensure_secure_url intentionally permits loopback HTTP for local development and native manuals bypassed the loopback check performed by the OpenAPI converter, an attacker who can serve a UTCP manual that a victim registers can cause the client to issue requests to services bound only to 127.0.0.1 on the victim host and have the response bodies returned to the caller (server-side request forgery). The http, sse and streamable_http protocols are all affected. Reach is limited to loopback, and exploitation further requires a loopback service that answers unauthenticated requests with useful data. Fixed in utcp-http 1.1.12, which rejects manuals fetched from a non-loopback origin that declare loopback tool URLs, keyed off the final post-redirect discovery URL.
CVE-2026-101058
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-101058
python-utcp
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "universal-tool-calling-protocol",
"product": "python-utcp",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "1.1.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "1.1.12",
"versionType": "semver"
}
],
"packageURL": "pkg:pypi/utcp-http",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-101058
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #4967 · Revision 1
- Added to Heist Feed
- Publisher date