CVE-2026-91143

goproxy through 15.3 Authentication Bypass via CONNECT

Published Sep 14, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
goproxy through 15.3 fails to apply HTTP proxy basic authentication to CONNECT tunnel requests, allowing unauthenticated clients to bypass credential requirements. Attackers can issue CONNECT requests to establish tunnels through the authenticated proxy without providing credentials, enabling arbitrary TCP traffic relay and access to restricted destinations.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Snail007
Snail007 goproxy
Vendors & Products Snail007
Snail007 goproxy
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description goproxy through 15.3 fails to apply HTTP proxy basic authentication to CONNECT tunnel requests, allowing unauthenticated clients to bypass credential requirements. Attackers can issue CONNECT requests to establish tunnels through the authenticated proxy without providing credentials, enabling arbitrary TCP traffic relay and access to restricted destinations.
Title goproxy through 15.3 Authentication Bypass via CONNECT
First Time appeared Goproxy Project
Goproxy Project goproxy
Weaknesses CWE-288
CPEs cpe:2.3:a:goproxy_project:goproxy:*:*:*:*:*:*:*:*
Vendors & Products Goproxy Project
Goproxy Project goproxy
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 24, 2026, 2:22 PM
Reserved
Sep 14, 2026, 8:35 PM
Status
Deferred
Published
Sep 14, 2026, 10:16 PM
Modified
Sep 23, 2026, 5:17 PM