CVE-2026-67339

GuzzleHTTP/guzzle versions before 7.14.2 fail to properly isolate Proxy-Authorization headers from origin servers in cURL handlers, allowing proxy credentials to be captured in origin logs during redirects or SOCKS proxy scenarios. This affects guzzlehttp/guzzle prior to 7.14.2 and can occur when...

CVE-2026-67339

guzzlehttp/guzzle versions before 7.14.2 fail to properly isolate Proxy-Authorization headers from origin servers in cURL handlers. Attackers can capture proxy credentials through origin server access logs when requests are redirected, bypassed, or sent through SOCKS proxies that Guzzle...

GHSA-94PJ-82F3-465W Guzzle: Proxy-Authorization headers can be sent to origin servers

Impact In affected versions, the built-in cURL handlers CurlHandler and CurlMultiHandler put every first-class request header in cURL's origin header list CURLOPTHTTPHEADER. These handlers are the default when the PHP cURL extension is available. They move Proxy-Authorization to the proxy-only li...

CVE-2026-55568

Summary (CVE-2026-55568) : Guzzle’s built‑in cURL handlers (CurlHandler/CurlMultiHandler) can downgrade an https:// proxy to plaintext when using libcurl older than 7.50.2, exposing proxy credentials and the CONNECT host/port. The issue occurs if an https proxy is configured and the app runs with...

CVE-2026-55568

Guzzle is an extensible PHP HTTP client. Prior to 7.12.1, in certain configurations, traffic expected to be protected by TLS on the hop to the proxy is transmitted in cleartext. Proxy authentication credentials the Proxy-Authorization header, proxy userinfo in the proxy URL, or CURLOPTPROXYUSERPW...

CVE-2026-55568 Guzzle: Silent HTTPS-Proxy Downgrade to Cleartext

Guzzle is an extensible PHP HTTP client. Prior to 7.12.1, in certain configurations, traffic expected to be protected by TLS on the hop to the proxy is transmitted in cleartext. Proxy authentication credentials the Proxy-Authorization header, proxy userinfo in the proxy URL, or CURLOPTPROXYUSERPW...