libcurl Vulnerability in HTTP Proxy Authentication Featuring Digest Credentials

CVE-2026-7168

What is CVE-2026-7168?

A flaw exists in libcurl that arises when transferring data over a specific HTTP proxy with Digest authentication. If a user successfully connects through one proxy (proxyA) and then switches to a second proxy (proxyB) using the same connection handle, libcurl incorrectly uses the Proxy-Authorization: header intended for proxyA during the request to proxyB. This mismanagement of header fields can lead to unauthorized access and exposure of sensitive information, thereby undermining the intended security of the proxy configuration.

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