CVE-2026-91143: Authentication Bypass Using an Alternate Path or Channel in snail007 goproxy
CVE-2026-91143 is a medium severity vulnerability in snail007 goproxy versions up to 15.3. The software fails to enforce HTTP proxy basic authentication on CONNECT tunnel requests, allowing unauthenticated clients to bypass credential checks. This enables attackers to establish arbitrary TCP tunnels through the proxy to restricted destinations without authentication.
AI Analysis
Technical Summary
The vulnerability in snail007 goproxy (<=15.3) involves a failure to apply HTTP proxy basic authentication to CONNECT tunnel requests. As a result, unauthenticated clients can issue CONNECT requests to create tunnels through the proxy without providing credentials. This allows arbitrary TCP traffic relay and access to restricted network destinations, bypassing intended authentication controls.
Potential Impact
Attackers can bypass authentication mechanisms on the proxy server, enabling unauthorized access to internal or restricted network resources by relaying arbitrary TCP traffic through the proxy. This could facilitate unauthorized network access or data exfiltration depending on the network environment.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the proxy server to trusted clients only and monitor for unusual CONNECT request activity.
CVE-2026-91143: Authentication Bypass Using an Alternate Path or Channel in snail007 goproxy
Description
CVE-2026-91143 is a medium severity vulnerability in snail007 goproxy versions up to 15.3. The software fails to enforce HTTP proxy basic authentication on CONNECT tunnel requests, allowing unauthenticated clients to bypass credential checks. This enables attackers to establish arbitrary TCP tunnels through the proxy to restricted destinations without authentication.
CVSS v4.0
Score 6.9medium
Affected software
snail007
goproxy
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in snail007 goproxy (<=15.3) involves a failure to apply HTTP proxy basic authentication to CONNECT tunnel requests. As a result, unauthenticated clients can issue CONNECT requests to create tunnels through the proxy without providing credentials. This allows arbitrary TCP traffic relay and access to restricted network destinations, bypassing intended authentication controls.
Potential Impact
Attackers can bypass authentication mechanisms on the proxy server, enabling unauthorized access to internal or restricted network resources by relaying arbitrary TCP traffic through the proxy. This could facilitate unauthorized network access or data exfiltration depending on the network environment.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the proxy server to trusted clients only and monitor for unusual CONNECT request activity.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-14T20:35:39.074Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa86eda55bf5e2cf5b12c50
Added to database: 09/14/2026, 22:02:02 UTC
Last enriched: 09/14/2026, 22:21:00 UTC
Last updated: 09/14/2026, 22:34:58 UTC
Views: 6
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