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8.7 High

CVE-2026-46527 cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library

Description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, When the server has called Server::set_trusted_proxies() with a non-empty trusted-proxy list, an attacker can send an HTTP request that includes an X-Forwarded-For header whose value parses to no valid IP segments. The code path then executes get_client_ip(), which calls front() on an empty std::vector—undefined behavior in C++. On typical implementations this manifests as abnormal process termination (denial of service). With Sanitizers enabled, you get an explicit runtime diagnostic. This vulnerability is fixed in 0.44.0.

Affected products and versions

Product Affected versions Fixed in
cpp-httplib 0.44 earliest → < 0.44.0 0.44.0
The 24 CVEs of cpp-httplib →
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