EUVD Vulnerability Catalog

EUVD-2026-105306

Severity: CRITICAL Base Score: 9.1 CVSS Version: 3.1

Vulnerability Description

An HTTP proxy can trick libcurl into sending the origin's credentials (Basic password, or a Negotiate/Kerberos ticket) to the proxy itself, by answering the `CONNECT` tunnel request with 401 `WWW-Authenticate:` instead of the expected 407 `Proxy-Authenticate:`.

CVSS Vector Analysis

Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

▪ Attack Vector (AV): Network

▪ Attack Complexity (AC): Low

▪ Privileges Required (PR): None

▪ User Interaction (UI): None

▪ Scope (S): Unchanged

▪ Confidentiality Impact (C): High

▪ Integrity Impact (I): High

▪ Availability Impact (A): None

Affected Vendors & Systems

Vendor curl

References & Advisory Links

Metadata Profile

Database Authority

European Union Agency for Cybersecurity (ENISA) EUVD

Assigner

curl

EPSS Probability

0.27

Known Aliases

GHSA-6qvf-c7g3-j256 CVE-2026-86414

Published On

2026-10-20

Last Updated

2026-10-30