CVE-2026-86414
Published:October 14, 2026
Updated:October 15, 2026
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:".
Affected Packages
libcurl (CONAN):
Affected version(s) =8.22.0 <8.23.0Fix Suggestion:
Update to version 8.23.0https://github.com/curl/curl.git (GITHUB):
Affected version(s) =curl-8_22_0 <curl-8_23_0Fix Suggestion:
Update to version curl-8_23_0Do you need more information?
Contact UsCVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Insertion of Sensitive Information Into Sent Data