utcp-http before 1.1.4 OAuth2 tokenUrl Trust Boundary Bypass (CVE-2026-101059) | HOL Guard CVE

High · CVSS 7.1CVE-2026-101059

utcp-http before 1.1.4 OAuth2 tokenUrl Trust Boundary Bypass

Answer in brief

CVE-2026-101059 records a High severity (CVSS 7.1) vulnerability in utcp-http before 1.1.4 OAuth2 tokenUrl Trust Boundary Bypass. The current sources do not mark it as known exploited. The current feed maps universal-tool-calling-protocol/python-utcp (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 27, 2026Updated Sep 27, 2026Source checked Sep 27, 2026First seen by HOL Sep 27, 2026Material review Sep 27, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps universal-tool-calling-protocol/python-utcp (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
universal-tool-calling-protocol/python-utcpgeneric	>=0 <1.1.4	1.1.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for universal-tool-calling-protocol/python-utcp.
Review the reported fix. Update universal-tool-calling-protocol/python-utcp to 1.1.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 27, 2026

Sources and claim methodology

Upstream source description

utcp-http before 1.1.4 fails to validate the OAuth2 tokenUrl field from remote OpenAPI specifications, allowing attackers to redirect credential submission to arbitrary endpoints. When a victim registers an attacker-controlled OpenAPI spec and invokes a generated OAuth2-protected tool, the library POSTs the victim's client_id and client_secret to the attacker-supplied token endpoint without URL validation.

Quoted source text, attributed separately from HOL analysis.