CPython HTTP Client Proxy Tunnel Header Injection via CR/LF
CVE-2026-1502 is a medium-severity vulnerability in CPython's HTTP client proxy tunnel handling. The issue arises because CR/LF bytes were not rejected in proxy tunnel headers or host values. This improper input validation allows attacker-controlled carriage return and line feed characters to be introduced into HTTP header construction for proxy CONNECT/tunnel requests, creating an HTTP header injection condition. Based on the available information, the affected component is CPython's HTTP client proxy tunnel handling logic; specific vulnerable functions or exact version ranges are not provided in the supplied content.
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