CVE-2026-34441
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk10th percentile - higher than 10% of all known CVEs
Summary
cpp-httplib is vulnerable to HTTP Request Smuggling. The server does not consume the GET request body, and on keep-alive connections unread bytes are interpreted as a new request.
Risk Assessment
An attacker can embed an arbitrary HTTP request inside a GET request body, potentially leading to unauthorized access or data manipulation.
Recommendation
Update cpp-httplib to version 0.40.0 or later.
Original NVD description (English source)
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.40.0, cpp-httplib is vulnerable to HTTP Request Smuggling. The server's static file handler serves GET responses without consuming the request body. On HTTP/1.1 keep-alive connections, the unread body bytes remain on the TCP stream and are interpreted as the start of a new HTTP request. An attacker can embed an arbitrary HTTP request inside the body of a GET request, which the server processes as a separate request. This issue has been patched in version 0.40.0.