CVE-2026-91143 goproxy through 15.3 Authentication Bypass via CONNECT
Unauthenticated attackers can bypass proxy authentication via CONNECT requests to relay arbitrary TCP traffic and access restricted destinations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-91143?
CVE-2026-91143 is a medium-severity authentication bypass vulnerability in snail007 goproxy, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-288
Which versions are affected by CVE-2026-91143?
How do I fix CVE-2026-91143?
No fix has been published for CVE-2026-91143 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-91143 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91143 exists.
Sources
Also known as GHSA-pvfx-f5gx-wj35.