What’s Vulnerable › Vulnerabilities

CVE-2026-101059: utcp-http before 1.1.4 OAuth2 tokenUrl Trust Boundary Bypass

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-27 · updated 2026-09-30
• Weakness: CWE-918

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.

Affected products

• universal-tool-calling-protocol python-utcp: before 1.1.4 — fixed in 1.1.4

How to fix

Upgrade to a fixed version: universal-tool-calling-protocol python-utcp 1.1.4. Check the vendor advisory for mitigations.

References

• https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-8cp3-qxj6-px34
• https://www.vulncheck.com/advisories/utcp-http-before-1.1.4-oauth2-tokenurl-trust-boundary-bypass
• https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-8cp3-qxj6-px34

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