cvedb.io
CVE-2026-55568
MEDIUM · CVSS 5.9
EPSS exploitation probability: 0%
Published 2026-06-23T16:17:02.990 · Last modified 2026-06-26T19:34:13.833

Summary

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 CURLOPT_PROXYUSERPWD) are sent without encryption, and the CONNECT target host and port for tunneled HTTPS requests are exposed. The built-in cURL handlers (GuzzleHttp\Handler\CurlHandler and GuzzleHttp\Handler\CurlMultiHandler, used by default whenever the PHP cURL extension is available) accept an https:// proxy. libcurl older than 7.50.2 silently treats an https:// proxy as a plaintext http:// proxy. The TLS connection to the proxy is never established, and the proxy leg is cleartext with no error or warning. An

Affected products

guzzlephp — guzzle

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.