gun has an Unexpected Status Code or Return Value vulnerability

Unexpected Status Code or Return Value vulnerability in ninenines gun gunhttp module allows a malicious HTTP server to force the client into raw protocol mode via an unsolicited 101 Switching Protocols response. In gunhttp:handleinform/8, when a 101 Switching Protocols response is received over...

GHSA-2J82-37XG-F9WP gun has an Unexpected Status Code or Return Value vulnerability

Unexpected Status Code or Return Value vulnerability in ninenines gun gunhttp module allows a malicious HTTP server to force the client into raw protocol mode via an unsolicited 101 Switching Protocols response. In gunhttp:handleinform/8, when a 101 Switching Protocols response is received over...

CVE-2026-43974 gun HTTP/1.1 client accepts unsolicited 101 Switching Protocols response allowing server-driven protocol hijack and OOM

Unexpected Status Code or Return Value vulnerability in ninenines gun gunhttp module allows a malicious HTTP server to force the client into raw protocol mode via an unsolicited 101 Switching Protocols response. In gunhttp:handleinform/8, when a 101 Switching Protocols response is received over...

CVE-2026-43974

The CVE concerns the gun_http module of the Erlang-based Gun library (gun_http) in the Gun HTTP client. Affected versions: Gun 2.0.0 up to but not including 2.4.0. Root cause: when a 101 Switching Protocols response arrives over HTTP/1.1, Gun only validates the Upgrade header syntax and the strea...

EEF-CVE-2026-43974 gun HTTP/1.1 client accepts unsolicited 101 Switching Protocols response allowing server-driven protocol hijack and OOM

Summary Unexpected Status Code or Return Value vulnerability in ninenines gun gun\http module allows a malicious HTTP server to force the client into raw protocol mode via an unsolicited 101 Switching Protocols response. In gun\http:handle\inform/8, when a 101 Switching Protocols response is...

GHSA-XQ2H-P299-VJWV Pingora vulnerable to HTTP Request Smuggling via Premature Upgrade

Impact Pingora versions prior to 0.8.0 would immediately forward bytes following a request with an Upgrade header to the backend, without waiting for a 101 Switching Protocols response. This allows an attacker to smuggle requests to the backend and bypass proxy-level security controls. This...

CVE-2024-23326: Unchecked Error Condition

Envoy is a cloud-native, open source edge and service proxy. A theoretical request smuggling vulnerability exists through Envoy if a server can be tricked into adding an upgrade header into a response. Per RFC https://www.rfc-editor.org/rfc/rfc7230section-6.7 a server sends 101 when switching...