python-utcp before 1.1.12 SSRF via Remote HTTP Manual
Summary
| CVE | CVE-2026-101058 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-27 18:16:31 UTC |
| Updated | 2026-09-27 18:16:31 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 7.1 HIGH from [email protected]
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-918 | CWE-918 Server-Side Request Forgery (SSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.1 | HIGH | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 7.1 | HIGH | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N |
| 3.1 | [email protected] | Primary | 6.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N |
| 3.1 | CNA | CVSS | 6.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighAttack Requirements
PresentPrivileges Required
NoneUser Interaction
PassiveConfidentiality
HighIntegrity
LowAvailability
NoneSub Conf.
HighSub Integrity
LowSub Availability
NoneCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
RequiredScope
ChangedConfidentiality
HighIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Universal-tool-calling-protocol | Python-utcp | affected 1.1.12 semver | Not specified |
| CNA | Universal-tool-calling-protocol | Python-utcp | unaffected 1.1.12 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/universal-tool-calling-protocol/python-utcp/security/advisori... | [email protected] | github.com | |
| www.vulncheck.com/advisories/python-utcp-before-1.1.12-ssrf-via-remote-http-manual | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: EQSTLab (en)
CNA: 232-323 (en)
There are currently no legacy QID mappings associated with this CVE.