CVE-2026-67339

A flaw was found in guzzlehttp/guzzle, where it fails to properly isolate Proxy-Authorization headers from origin servers when using cURL handlers. A remote attacker could exploit this vulnerability when requests are redirected, bypassed, or sent through SOCKS proxies that Guzzle misclassifies as...

CVE-2026-69246: Incorrect Behavior Order: Validate Before Canonicalize

Guzzle is an extensible PHP HTTP client. Prior to 7.15.2 and 8.0.1, Guzzle gives a transport the request URI as text and supplies the Host header separately. The cURL handlers set CURLOPTURL to the URI exactly as written and push that Host into CURLOPTHTTPHEADER; StreamHandler does the same throu...

Duplicate Advisory: Guzzle: Proxy-Authorization headers can be sent to origin servers

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-94pj-82f3-465w. This link is maintained to preserve external references. Original Description guzzlehttp/guzzle versions before 7.14.2 fail to properly isolate Proxy-Authorization headers from origin servers in...

GHSA-32RQ-JHR7-M3HH Duplicate Advisory: Guzzle: Proxy-Authorization headers can be sent to origin servers

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-94pj-82f3-465w. This link is maintained to preserve external references. Original Description guzzlehttp/guzzle versions before 7.14.2 fail to properly isolate Proxy-Authorization headers from origin servers in...

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...

CVE-2026-67339 guzzlehttp/guzzle before 7.14.2 Proxy-Authorization Header Disclosure

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...

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...

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...

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

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

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...

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...

Missing Encryption of Sensitive Data

Overview Affected versions of this package are vulnerable to Missing Encryption of Sensitive Data due to the fallback on insecure plaintext http:// option proxy in cURL handlers. An attacker can gain unauthorized access to sensitive data such as proxy negotiation and proxy credentials by...