Security Advisory

CVE-2026-21428

CVE vulnerability detail — eXtreme Datacenter Security Operations

Published 2026-01-01 17:54:43
Last updated 2026-01-02 18:50:20
Assigner GitHub_M
State PUBLISHED

Description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.30.0, the ``write_headers`` function does not check for CR & LF characters in user supplied headers, allowing untrusted header value to escape header lines. This vulnerability allows attackers to add extra headers, modify request body unexpectedly & trigger an SSRF attack. When combined with a server that supports http1.1 pipelining (springboot, python twisted etc), this can be used for server side request forgery (SSRF). Version 0.30.0 fixes this issue.