CVE-2026-86414

CRITICAL
INFO Priority: 0.02 BB Relevance: 78/100
Published: 2026-10-20 Modified: 2026-10-30 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: High
I: High
A: None

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:`.

Weakness Classification (1)

Affected Software (172)

VendorProductVersion
curl curl 8.22.0
curl curl 8.21.0
curl curl 8.20.0
curl curl 8.19.0
curl curl 8.18.0
curl curl 8.17.0
curl curl 8.16.0
curl curl 8.15.0
curl curl 8.14.1
curl curl 8.14.0
curl curl 8.13.0
curl curl 8.12.1
curl curl 8.12.0
curl curl 8.11.1
curl curl 8.11.0
curl curl 8.10.1
curl curl 8.10.0
curl curl 8.9.1
curl curl 8.9.0
curl curl 8.8.0
curl curl 8.7.1
curl curl 8.7.0
curl curl 8.6.0
curl curl 8.5.0
curl curl 8.4.0
curl curl 8.3.0
curl curl 8.2.1
curl curl 8.2.0
curl curl 8.1.2
curl curl 8.1.1
Showing 30 of 172 entries

Bug Bounty Relevance

78 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

9.1 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploitation Probability

0.27%
Raw Score 0.002660
Percentile 18.6%
Date 2026-10-30

EPSS Trend

2026-10-30
0.00266
2026-10-29
0.00266
2026-10-28
0.00266

Intelligence Sources

mitre ref →
nvd ref →