CVE-2020-11709

The CVE-2020-11709 issue affects the cpp-httplib library prior to 0.12.4, where CRLF injection is possible because input is not filtered when setting the Content-Type header in HTTP requests created by Patch, Post, Put, or Delete. The vulnerability arises in untrusted input used to influence head...

CVE-2026-45352

The CVE-2026-45352 issue affects cpp-httplib (header-only HTTP/HTTPS library). Before version 0.43.4, the ChunkedDecoder::read_payload routine parses the chunk-size in chunked Transfer-Encoding with std::strtoul(), which can silently accept a minus sign. This allows negative chunk sizes (e.g., "-...

CVE-2026-28435

CVE-2026-28435 affects the cpp-httplib single-file header-only library. Before 0.35.0, the library does not enforce a payload max length on decompressed request bodies when using HandlerWithContentReader with Content-Encoding: gzip (or other encodings). A small compressed payload can expand beyon...

CVE-2026-33745

The CVE affects cpp-httplib (a C++11 single-file header-only HTTP/HTTPS library). Before 0.39.0, the HTTP client forwards stored Basic Auth, Bearer Token, and Digest Auth credentials to arbitrary hosts when following cross-origin redirects (301/302/307/308). A malicious or compromised server can ...

CVE-2025-52887

cpp-httplib (C++11 single-file header-only library) is affected by CVE-2025-52887 in version 0.21.0 where there is no limit on the number of HTTP header fields and header memory is not released on disconnect, potentially exhausting system memory and causing server crash or unresponsiveness. Remed...

CVE-2025-53629

CVE-2025-53629 affects cpp-httplib (C++11 single-file header-only HTTP/HTTPS library). Prior to version 0.23.0, handling of incoming requests with Transfer-Encoding: chunked could allocate memory arbitrarily on the server, risking memory exhaustion. The vulnerability is fixed in 0.23.0. Related C...

CVE-2026-31870

cpp-httplib prior to 0.37.1 uses streaming API (httplib::stream::Get, httplib::stream::Post, etc.) and directly calls std::stoull on the Content-Length header without validation, causing unhandled exceptions and a deterministic crash via std::terminate() when a non-numeric or out-of-range value i...

CVE-2026-54919

cpp-httplib on Mbed TLS and wolfSSL backends was vulnerable to a TLS certificate chain verification bypass for IP-literal hosts (affecting v0.31.0–0.46.1) when server verification was enabled; SSLClient/Client could skip chain validation and Mbed TLS WebSocketClient could skip verification. The i...