CVE-2026-86414
Published: October 15, 2026Last modified: October 27, 2026
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:`.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.1 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | curl | Fixed (8.23.0-r0) |
| 25 LTS | curl | Fixed (8.23.0-r0) | |
| Stream | curl | Fixed (8.23.0-r0) | |
| Hardened Containers | Stream | curl | Fixed (8.23.0-r0) |